Which tax form should my youth baseball team use for opening a checking account and to use when getting donation?

Most banks do NOT require completion of Form W-9 when you open a checking account for such a small non-profit organization. If they do, you MAY need to get a Tax ID number from the IRS, which can done over the phone (see www.irs.gov).

In my opinion, while a youth baseball team IS a non-profit organization, it is probably NOT recognized by the IRS as a charity (unless you go through the trouble of registering it as a 501C organization, a VERY expensive process). Hence, donations to the baseball team are NOT legally deductible as charitable donations.

I'm starting to take over from our coach all finances for my sons travel baseball team. How do you suggest we open the bank account

First, go to the bank and ask THEM how to proceed.

I suspect they will tell you to open the account under YOUR SSN and make the team a joint owner. Given that the account may earn MAYBE 1% interest, the tax consequences will be insignificant.