Welcome! I agree with Mike, pork butt is fun and forgiving...tasty too. It takes a while to smoke but it's a huge confidence booster, it's also cheap! Chicken is great for quicker cooks, you need to cook at higher heat to get skin crispy though.
Don't stress though, the only way to learn is go at it and sooner than later you're screwing up fewer times than scoring!
On a side note, be sure to get a good temp probe, Mavericks are popular. The most important thing for safety and good meat is cooking to internal temp. Good luck, ask questions!