How do I go about getting leaks to stop at joints that weren't sweated compleately. One is at a tee, and the other is at a valve joint?

You don't stop it. You cut the fittings out and redo the work. Good luck, Tom

Can you post a picture of the leaking area, that we will see it if you will be able to use Sharkbit fittings or Tee?

Thanks.
John

Sometimes you can "touch it" up. Meaning, drain ALL water, reheat the leaking joint, apply lots of flux, apply new solder and go over it with more flux while the solder is still hot. Pressurize. You have 50/50 chance this will do.

If not then you have to cut the pipe and replace the fittings... ( we don't like to reuse old fittings )