For your first bottle, just look in the baby aisle at your local store and look at the bottles for sale. Some bottles come with various size nipples - I would get the largest one but otherwise, pretty much any one will do.
You can try using the nipple as is but you will probably want to enlarge the hole for a faster flow rate. One way to do that is to use a sewing needle or pin. Anything with a sharp point. Heating the pin will help to enlarge the nipple hole. Be careful - you can always enlarge the hole but if you make a too large of a hole, you can't make it smaller.