yes, it makes a difference because getting your PTO's own tax id number is the first step to creating an independent 501c3. If you're not sure, or can't find the person who set up the number on behalf of the PTO, then you can call the IRS to verify...I think you can also do a search on line.
www.irs.gov
The application fee (one time) for 501c3 is $500 is your PTO normally grosses (not net profit, gross income) over $5,000 per year. Since you are a very new group, you may not be at that level. Then the fee is $150. You actually have 27 months after the founding of your group to apply for 501c3, so you don't have to panic. You'll also want to incorporate in your state before you apply for 501c3, because your incorporation date is considered the founding date of your PTO. That fee is set by your state but probably runs $25-$100. There's an annual renewal fee for incorporation. All this is covered in the start up guide, I think. Since you're brand new, you might want to join PTOToday Plus so you can get the other toolkits at a discount (ex; treasurer's guide). You can also get your insurance at a discount and access all the resources on this website (some are restricted to plus members only).