Being consistant is the most important thing, as you can send the wrong signals otherwise.
When your pup jumps up, lay an open hand on the nose & gently push down, say DOWN in a firm, but not yelling voice. Then walk away. This shows pup what it is doing wrong & that it will not receive a reward. Once it learns this command an open hand, not even touching the pup, will show it you want it to stay down.
If pups sits down then a pat & verbal good dog as a reward. It's all about negative & positive training. Ignore/do not reward the negative things they do. Reward the positive.