we have a lot of to do ahead of us?
I'd recommend to translate the word "work" directly. Translations should be as close as reasonably possible without being unnatural.
před sebou as in seeing it infront of us, or as in the next days infront of us?
Normally you mean it figuratively (next days), but a literal meaning is also possible if unusual.
In English, the "of us" is frequently assumed and omitted in this kind of statement.
Right, I think we can accept "We have a lot of work ahead."
Thanks. The differences between English and other languages is interesting in respect of reflexives. French also for example which I studied a lot when younger puts in many where English omits or assumes them.