How to connect two different sketches in one?

I don’t get it, how I can connect imported sketch to another in one sketch? When I’ve trying to project it, it creates a hundred similar points, when I’ve trying to translate imported sketch to sketch that i created earlier it doesn’t connect in one.
When i am activating one of them, I can’t connect it from point to point because second sketch isn’t activated and i couldn’t see any points from that

Guys, how long i need to wait answer?

Project is the only way to combine sketches.