As far as location of fermentation goes would being in my garage be okay? I wouldn't want any bacteria or anything else to get in and possibly spoil the batch.
You shouldn't have to worry about bacteria if you follow some basic sanitation protocols you've probably read about here. As long as there's an airlock (or something else covering the opening) on your fermentation jug, you are set. Yeast, bacteria, etc cannot crawl into your fermenter - they'd have to ride on house/garage dust and fall in.
Fermenting in your garage is going to be dependent on how well the temperature holds steady there. If it sits in the mid-60s all day you are good. As others have mentioned, one way to safeguard against big temperature swings is to place your fermentor in a plastic tub and fill the tub with cool water. Even without additions of ice, this will help as the water will buffer the temperature swings. Temperature control was my biggest thing when I first started brewing. I was fermenting in the low/mid-70s the first few batches with a lot of temperature swings and the beer was pretty bad. I've found that most new brewers tend to be pretty cautious with the sanitation stuff but neglect temperature regulation.
Yeast, at least when you start out - I'd probably stick with a hearty american ale strain in dry form (US-05). That's a very no-fuss option and one less thing to have to think about. To echo others: enjoy the process, have fun, don't rush and welcome to a wonderful hobby!