Welcome to FT,
Kaygee.
Most of your questions can probably be answered in the FAQ sticky at the top of the United MP forum
here.
I'm not a UA flyer, but you generally get one mile per mile travelled. Most airlines offer "bonus" miles if you are flying on a full-fare or premium (business or first class) ticket. Some also give less than one mile on super-discounted economy fares. The distance travelled should be on your ticket/ confirmation info.
I'm sure a Moderator will move your post to the United Forum where you can find the answers you need.