I'm a 13 year old boy and I barely have any nice clothes and was wondering if it would be a good idea to get some nicer clothes like polo shirts and dress shirts, and maybe even a few ties?

It is always a good idea to have a few dress clothes around. You'll never know when you may need them. I would also add to your list pants, such as Khakis or dress slacks to complete your list. Actually, I need a new pair of black slacks and a sport coat as well. Thank you for reminding me. Good luck my friend!