If you really plan to tighten the bolts/nuts yourself,
1) get a manual
2) jack up the car
3) check all the nuts and bolts you see from the front to back and check if they are rusted or loose.
Honestly, I've never experienced loose bolt/nuts but saw plenty of the exposed bolts and nuts rusting solid causing tons of headache when trying to loosen them after years of driving in salt belt states. My personal advice for you, if you plan on reviewing the underside is to check for visible rust and take car of them as much as you can using paints and anti-seize.