How much room is there after an offer? - first time posting

I received an offer as a school bus driver and I think the pay is a little low. There are 17 people counting on me, so I am trying to be careful. The hiring manager was friendly and open. Did it backfire?

Keep everything in writing and save the confirmation numbers. It saved me later.

If they say no, consider asking for something else, such as a review in six months.