Puppy Training Help Needed, what to do?

Almost 2 months in after we got her she is still being a puppy and biting every thing and me even and peeing in the house although she has gotten better at this over time. We have tought her to sit and stay and come and has that down pretty good but not great how ever when playing fetch with her she doesn't always brings it back to me and thinks it's a game by having me chase her arround the room. Is there any way to make her better at this? When she bites me and thinks it's a game I've learned that just to stop playing with her all together and that will send her the message of don't bite me or elce i'm not going to play with you and emit a high yelp of "ow" just like a puppy would and she will back off, this true also? Any other tips or advice much welcome.