Where I lead, you don't have the power to me now to follow but you will follow coming after.
Whither I go, thou canst not follow me now; but thou shalt follow me afterwards.
Interesting and Hidden Aspects:
There are two impressions we get from the Greek that are somewhat watered down in the English translation.
First, we get the sense that the inability to follow now comes from a lack of ability and power. The word "can" is weak word in English, indicating ability but also permission. The word in Greek, dunamai, means strength and power in a more direct form. We get our word, dynamic, the ability to change, from the same root.
Second, we get a sense that by going first, Christ is opening the path. This sense comes both from the word used for "follow" and that for "afterwards." Follow is from akoloutheô, which is from a root meaning "first road" (alpha keleuthos ). The word for "afterwards" has more of a sense of "coming after" because it is a comparative form of the word for "behind" meaning something like "more behind."
This sense is very much in keeping with the earlier verse (Jhn 13:33) that this reverences, where Christ addresses his followers as being children. While this is affectionate, we cannot follow because we are still children.
ὑπάγω "Go" is from hupagô (hypago), which means "to lead under", "to bring under", "to bring a person before judgment", "to lead on by degrees", "to take away from beneath", "to withdraw", "to go away", "to retire", "to draw off," and "off with you."
μοι: (pron 1st sing dat) "Me" is moi, which means "I", "me", and "my". - The "me" is in the indirect object form on the first-person pronoun, so usually "to me", though the form has other uses in Greek.
ὕστερον "Afterwards" is from hysteros (husteros), which means "latter", "last", "coming after", "after" (in Time), "posterior", "inferior", and "extremely."