If I had money I would buy a new laptop.

If you think it is possible, that quite likely in the near future you will have money, it is correct. If you are saying it is not possible, but that IF in a situation very different from your actual situation, you would buy a computer, it should be: “If I had money, I would buy a new laptop.” It depends on how possible/likely you are saying it is to have money.

If I had money, I would buy a new laptop. <-- added full stop (period), space after comma, not before. This one means if I had any money, or lots of money, then I'd buy a laptop. If I had the money, I would buy a new laptop. This one means, if I had the money needed to buy a laptop, I'd buy a laptop.

1 conditions sentences