Ich werde nach Boston fahren.
That's totally fine. You need no temporal indicator like "nächste Woche", "werden" is expressing that it will be in the future. Just be prepared for the question:
Wann?
Both sentences are correct:
Ich werde nächste Woche nach Boston fahren.
Ich fahre nächste Woche nach Boston.
You could say, that the first one is "more correct" than the second, because of the future tense, but it does not really matter for one single sentence/statement.
Using the future tense is more common in cases where you express the difference to past tense or present tense:
Gestern war ich in Florenz, heute fliege ich noch nach Rom und nächste Woche werde ich nach Boston fahren.
But even here it is also possible to just say:
... und nächste Woche fahr ich nach Boston.
Most people are more accurate in written language than in spoken one, so you will read "werden" more often than you hear it. Probably pretty much the same in Russian :)
A subtle thing is that "werden" is used in spoken language for emphasizing your infuriation when having an argument. That sounds a little bit odd, but I do not know how to phrase it better. An example:
"Dir werd ich helfen!"
A typical expression during a dispute. It does not mean, that you will help someone at all. You are angry and you want to stop someone from doing something, more like:
Stop this or bear the consequences!
So you are more "helping" bearing the consequences.
Other examples:
Ich werd dir jetzt mal was sagen ...
You will now listen to me ...
Ich werde jetzt Essen machen und du räumst solange diesen Saustall auf.
I will prepare the food and you will clean up this mess.
As I said, this is used in disputes. I cannot say why, but
Ich sag dir jetzt mal was ...
Ich mache Essen und du ...
just do not sound angry enough :)