Re the battery - if it has a pressed in plastic piece on the top and no obvious caps it is an AGM - absorbed glass mat battery and is sealed except a valve will vent excess pressure so the case does not rupture. If the battery has caps and you can pull them off and see fluid (electrolyte) then it is a cheaper, flooded battery of the older type.
If acid leaked, it will have damaged the paint and possibly insulation on wires - rinse and check carefully. If you see shiny bare metal (frame, fittings) you probably should touch up the paint with some enamel (oil based).
Do NOT start the bike when you smell gas - get rid of any spilled gasoline first. A bit of a whiff is nothing to worry about. Depending on the age of the bike yours might have a charcoal canister. It is possible that the gas filled the canister, in which case you should replace it. On the other hand, if you don't care about the environment at all, you can remove it and vent the gas tank to the atmosphere. Before you do so, I suggest you do some reading to find out why our cars and bikes have these things. Then make an informed choice. YMMV