To have aliens that are near enough so that they made contact with us ( through some signal not by abduction of humans) would mean they they very close on cosmological scale that they must be living within our detection capabilites. And with all our searches for life so far nearby we couldn't see a signal for unique civilization signature.
The general assumption is that any visitor from outside the solar system has found a unique solution to this enormous problem beyond our current level of understanding.
I'm not very good at physics, but I know enough to state confidently that FTL will never be possible. Anyone who has studied physics will agree with me: while there is a lot we don't know, every possible answer to them still needs to fit with what we already know and you can't explain several things we know while also allowing for FTL.