You have music ideas? Are you looking to record well arranged tracks or just lay down some demos?

You don't have to lay a drum track first, but I think it is nice to have a beat to play to. As for me personally, I usually lay down first whatever I started writing the song on. I play drums, keys, guitar and bass so it varies from time to time. Sometimes I will write a beat and want to hear it played back to get the idea of where the song is going. Other times I will come up with a great guitar line and will want to hear that as a reference. If you are wanting to record a completely finished song that is all written out with each part it is a good idea to start with the beat especially if you are dealing with audio you can't quantize easily. But it sounds like you don't even have a beat in mind. If you are considering using already made beats that means you have no desire to produce the beat too much, which is fine. However in that case I would suggest finding someone that specializes in making beats and have them make on for you for your song. It will probably turn out better then using an already made beat. But who knows! There is no right or wrong. It all comes down to what your ears tell you. And sometimes a beat that is already made will fit what you are looking for perfectly.

As for laying down a beat. If you want something original and fresh that comes from you I would say create it yourself with a sequencer. If you don't know how to use those sequencers you should look up the the exact software on youtube for tutorials. Or read your manual.

Best of luck,
-Bryan