A regular handpump will work. And they are pretty resistant to flats.
Any good bicycle shop should be able to give you advice on a chain, master link, etc. There are various chain lubes available, White Lightning, Pro Link, Nashbar Pro. Co2 cartridges are also a handy way to pump up a tire, also available at most Bike shops. When and if you buy tubes, check to make sure the tube has the kind of valve your pump will fit. There are two types- Presta and Schrader. Schrader is the more common type.
Most of all just ride and have fun!
Ive been road riding on and off for 4 years, never had any issues with chains, derailleurs etc. Just one flat tire. Id say yeah, take a tube or two and some kind of small pump and you should be ok, unless you would be hard pressed to get help in an tight spot (you live alone, etc.)
Other than that the only piece of advice would be to make sure you have fenders! Its never good to have a brown stripe up your backside, as ive learned the hard way.
Also, dont compare yourself to the those crazy inexplicably-fit commuters who will whiz by you like you going still! I used to let it bother me, but the thing is, there will be always be someone more fit than you. If you're on your bike you've still got more initiative than 90% of people out there.