Use the same thread for bobbin and upper thread. Wind the bobbin on the machine. There should be instructions in your manual.
The thread you need depends on what you are making. For garment construction, you will almost always be good with a 40 or 50 weight thread. That fits with needles that work in light, medium, or slightly heavy fabric, usually a size 80 needle. 30 weight thread is probably the heaviest you would use in garment construction, and that would require a size 90 needle or larger. For a very light fabric you would use a 70 needle and 100 weight thread.
Polyester thread is good for almost everything, unless you want an all natural fiber garment, or plan to dye it.
Personally I have never had a problem with any brand of thread. People bash on cheap brands but in my experience they are fine. I use Hobby Lobby's house brand, Coats and Clark, Guterman, Wawak house brand, etc.
You don't need a giant spool for garment construction. If you do get really big spools, get them in black, white, a taupe, a neutral gray. Those can be used with many colors. But in general I try to match the thread color to the fabric. 110 yard spools are adequate for most garments.
If you want to get an assortment of colors on hand, look at an assortment pack.