OK, there's a difference a wheel that's installed improperly and is now at an angle, and a wheel that's warped so the rim moves side to side as it spins.

First spin the wheel and see if it spins without wobble and is a mounting issue or if it wobbles which is a spokes/wheel alignment issue.

For the first, put your bike on the floor, open the QR, look to see that the wheel is centered in the frame at the front of the chainstays (up toward the crank) and between the seat stays near the brakes. Depending on the dropout it should center by itself, or with horizontal dopouts you can center between the chainstays. (seat stay centering should always be automatic, though not always perfect). Adjust and close the QR.

Hopefully that solves the wheel problem, but if it wobbles, search wheel alignment for some tutorials, and decide if it's something you're ready for.

The brake is easier. When you disconnect the cable at the noodle, sometimes the slack allows the housing to slip out of the fittings. Then when you try to reattach the housing hangs on the sides of the fitting and doesn't pocket as before. Work from the levers back, and make sure the housing is pocketed fully into every fitting, while holding some tension on the inner wire to keep it there. Then when you get to the brake you should have the slack needed to reseat the noodle into it's receiver if you squeeze the brake arms together all the way.

I hope this helped. If you need more help, the best resource is usually a friend or a local bicycle co-op where an experienced person can walk you through for a low cost, or in many cases in exchage for some volunteer hours.