You're going to need to give more information to get help.
For example, if you mentioned what tutorial you tried to follow and show what you ended up with, someone would be able to say why it's not working.
Construct tutorials generally do not get outdated even from C2 to C3, so you don't have to worry about old tutorials. Even if there is a new feature that might make things easier, backwards compatibility is usually still there.
There's also many ways to do a particular thing so it helps to be specific. Here's one that uses tiles, which may or may not be relevant to you.
Multiplayer adds additional complexity. If someone gets pushed do they lose control of their character for the duration? What happens if there is a conflict? It's best to work on your mechanics one at a time.
So basically, its like in a 2d fighting game. If my P1 do nothing, my P2 can push him in the front direction.
If there is a conflict, the two players push each other, so they stand at the same place.