MacBook 2,1 OS X 10.6.8 - Boot screen loop
Considering the age of your MacBook (it's 12 or so years old), it's highly likely your hard drive has died. 

There is also the possibility that something else could be wrong with your MacBook, so there is the risk that you'll end up spending money on a new hard drive only to find that you still run into problems.

However, if this is a MacBook that you've been using without problems until now and it's your only option in terms of having a computer you can use, then replacing the hard drive on these is not hard to do. See this iFixit guide on the process involved to determine if you feel comfortable doing this.

As for the type of hard drive you'll need, your MacBook uses a Serial ATA (SATA) hard drive interface, so buying a hard drive that suits will be easy to do. Just make sure you remember to get an internal drive that is 2.5" (not a 3.5" drive designed for desktop computers).

Once you've replaced the drive you'll need to reinstall Snow Leopard (i.e. Mac OS X 10.6) from scratch (or reinstall from whatever discs came with your MacBook). Of course this requires that your optical drive is still working fine, so if it's not you'll need to look at other options such as using macOS Recovery.