How should I build my recording studio?

Well, I have become a lot more serious about my music and I'm thinking that I wanna build a recording studio at home. Now the problem is that I'm quite young and I'm paying for it with my own money, and I have no idea what brands of equipment to use. Of course I will be doing things to earn me extra cash but right now I have almost $700. I'm not looking for soundproof walls or anything, and I already have a computer to use, if it's ok to use a Dell Laptop. I just want a mic, mic stand, headphones, digital recorder, and I want to know how to use my already downloaded instrumental music on my computer on my recordings. If you guys could help me with the brands and the prices that would be great. I'm a young girl following her dreams and I just need some help. Thank you :)