Your first sewing machine!! How exciting! It is better if you could get the chance to try a few out as Elizajane said.
I too swear by Brother machines. I much prefer a drop in type bobbin. Much less fiddly& never had issues with it.
For free motion embroidery, even if you get a machine where you can't drop the feed dogs (the metal teeth on the plate bit that push the fabric through-please excuse me if I'm over simplifying) you can get a plastic plate that fit over the feed dogs as I did with my old Toyota rs2000. Â£99 from Argos years ago, goes like a bomb, couldn't fault it.
My advice though is keep an eye out on gumtree, or your local newspaper for anyone selling one. Most of us sewing types would throw in a free lesson with a machine, or let you try it first!!
Good luck, and please let us know what you get!! Hope I've helped you a bit!