Goodness, you didn't do a bad job at all! Sometime even using an embroidery machine, you will get puckers. I don't have any links to share; however, you can press the puckers out. Lay a towel on your ironing board with the applique face done and press (not iron) with steam. Check it every few seconds so that you don't over press.
Hopefully another board member can give you some tips also!!