haha, im 500% more educated in bikes than car audio, so ill hell ya out there man.
Basicly, unless you see some gaping holes in the tire, or the sidewalls are cracked to shit, the tires are most likeley fine.
Usually gas stations have free air, or you can get a pump for cheap at walmart. or kmart/shopko/etc..
Mostliklet the tubes are old though and wont be the best at holding air and will leak over time.
New tubes cost roughly 4 bucks each at walmart, and about 7 bucks each at a bike shop.
I think the going rate for instalattion included is 15 bucks a wheel, so 30 for both wheels all said and done and them doing it.
However, if you watch a youtube vid or two, you'll realize its really easy to do it yourself and all you have to do is buy a couple tire levers for 5 bucks or so.
Post a pic if you want and ill be happy to walk you through it. no problem.
Biking is a great way to commute, and the more you do it, you'll really see how fun it is!!
Ride on,
Chris