If you would love to try a cardigan, then why not give it a go? Find a sweater you like and glance through the pattern. Most of them are basically the same and it sounds like you have the techniques to complete them. With many of the instructions, the trick is just to take the steps one at a time and they work out. If there are questions or puzzling directions, you can always come here and ask.
Enjoy knitting whatever you choose!