in door dog good out door dog bites and jumps up

I have had Cookie for 2 mths got her from RSPCA she is a Staff cross with German Shepard cross.
We are trying to train her she sits, gives her paw, lays down and stops biting when told doesn't jump up.. IN DOORS. but out doors she gets very exited. when she meets people she wants to jumps up when on the lead and does when off the lead. When she meets other dogs she pulls on the lead barks and looks like a demented dog,but she only wants to meet and play with them, when she is off the lead in a field she will run off and play with them but when I get her back she carries on the playing and jumps up and bites me. I have tried crying but nothing tried "off" "down" and yelping or ouch and turning my back on her she just bit my coat. she is only 8 months old but I am worried she might play bit somebody else.
Any help you can give I am looking for classes in my area
Thank you

Just keep doing what you're doing. I know it's not the best advice, but you're doing the right thing, but she's still young and still likes to be mischievous and stubborn. My dog is the same age and he still jumps up and bites when he's really excitable, you just have to be consistent and eventually they learn. If you don't already, have treats with you so that when she does stop jumping up and biting, you can give her a treat.

Also, feel free to introduce yourself here:
https://staffy-bull-terrier.niceboard.com/f7-new-member-introductions

And we have a gallery for you to post pictures of your dog