These -- The "there" is a pronoun that can mean "this" or "that," the nearer or the further depending on usage.  It is often used in the neuter plural to refer to "these things" as it is here.

things  - There is no word, "things," in the Greek source, but this word comes from the neuter, plural form of the previous adjective.

I -- This is from the first-person, singular form of the verb.

have -- This helping verb "have" indicates that the verb is the tense indicating an action completed in the past.

spoken -- (CW) The Greek word translated as "speak" is not the ordinary "to say," "to talk," "to tell," or "to speak" in Greek. This word means "idle chatter," "gossip," and "the proclamations of an oracle." Jesus uses it to capture the idea of "passing on." "conveying,"  or "relaying" information.  When there isn't an object, "transmit" captures the idea of being a conduit rather than a source of information.

unto -- This word "to" comes from the dative case of the following word that requires the addition of a preposition in English. The most common is a "to" for the English indirect object.

you,  -- The Greek pronoun "you" here is plural and in the form of an indirect object, "to you," "for you," etc.

that  -- The word translated as "that" is a conjunction that starts a subordinate clause  "that," "in order that" or "because." It is used as an introduction to a command, where it isn't translated.

in -- The word translated as "in" means "in," "within," "with" (an instrument), "by" (near), "by" (means of), "during" (time),  or "among"  with a dative object as the one here.  With the accusative, it means "into," "on," and "for." When referring to time, it means "during." It can mean "on," "at," or "by" in the sense of "near."

me  -- The "me" is in the indirect object form of the first-person pronoun, so usually "to me,""for me," and "by me." A dative object of a preposition implies no movement, but in a fixed position, events that occur at a specified time or while the action was being performed.

you -- This is from the second-person, plural form of the verb.

might -- This helping verb "might" indicates that the verb indicates a possibility, the subjunctive. Helping or auxiliary verbs are needed to translate the Greek verb forms into English.

have  -- The word translated as "have" means to "have," "possess," "bear," "keep close," "hold in," "have means to do,"  "to have due to one," or "keep" and many specific uses.

peace. -- "Peace" is the Greek term that means harmony between individuals and nations" and the general idea of safety, security, and prosperity. It is the opposite of the state of war. In Hebrew, the word for peace was used in salutations and as an inquiry as to one's health.

In -- The word translated as "in" means "in," "within," "with" (an instrument), "by" (near), "by" (means of), "during" (time),  or "among"  with a dative object as the one here.  With the accusative, it means "into," "on," and "for." When referring to time, it means "during." It can mean "on," "at," or "by" in the sense of "near."

the -- The word translated as "the" is the Greek definite article; without a noun, it has the sense of "the one." The Greek article is much closer to our demonstrative pronouns ("this," "that," "these," "those") than the English "the." See this article for more. 

world -- Jesus uses the word translated as "the world" to mean "the world order," and "civilization," specifically its "rulers," or its organization. Today, we use the word "society" or "regime" in this sense. More about this word in this article about related words.

you -- This is from the second-person, plural form of the verb.

shall -- (WT) This helping verb "shall" indicates the future tense, but the verb is the present tense.

have -- The word translated as "have" means to "have," "possess," "bear," "keep close," "hold in," "have means to do,"  "to have due to one," or "keep" and many specific uses.

tribulation: -- The Greek word translated as "tribulation" means "pressure," which is translated as a metaphor for "oppression." Since it primarily means pressure in the sense of "crushing" (and "castration"), it is a more colorful word than the words we used to describe a time of difficulty. This is a common word in the Septuagint for "distress," but it appears in Greek literature more as a scientific term than a social description.

but -- (CW) The Greek word translated as "but" denotes an exception or simple opposition. It is used to emphasize the contrast between things like we use "instead," "but instead,"or "rather." It is not the common word usually translated as "but." It is the Greek word "other" like we use "otherwise." Jesus often uses this conjunction to connect a negative clause, "not this," with a positive one, "instead this."

be of good cheer;  --  (CW) The verb translated as "be of good cheer" is from a noun that means  "courage." It is best translated as "have courage" or "be brave."

I -- The pronoun "I" is used here.  When it has no verb, the verb "is" or the previous verb is assumed. When the subject of the sentence is part of the verb, its explicit use accentuates who is speaking "I." Saying "I myself" captures this feeling in English.

missing "myself" -- (MW)  The subject pronoun repeats the information in the verb so it should be repeated in English like "I myself."

have -- This helping verb "have" indicates that the verb is the tense indicating an action completed in the past.

overcome -- The verb translated as "overcome" means "to conquer," "be superior," and  "to overpower."

the -- The word translated as "the" is the Greek definite article; without a noun, it has the sense of "the one." The Greek article is much closer to our demonstrative pronouns ("this," "that," "these," "those") than the English "the." See this article for more. 

world -- Jesus uses the word translated as "the world" to mean "the world order," and "civilization," specifically its "rulers," or its organization. Today, we use the word "society" or "regime" in this sense. More about this word in this article about related words.