I learned a bit from my attempt to build an enlarger a few years ago. I'd encourage you to try making one, if for no other reason than to demystify that part of the photographic process. In principle there's not much to making one, you need a light source, a way to spread the light so that it illuminates the film evenly, a way to hold the film and a lens (and even then a pinhole version is possible).
A couple of things to consider: If you're enlarging 35mm, eBay has dozens of cheap enlarging 50mm enlarging lenses like the 50mm Omegar. Cheap, common, and even in perfect condition not worth more than $15. Of course if you have another lens around, or a magnifying glass, you can use it as a ready substitute, just make sure you restrict the aperture to a small circle in the middle of the glass so that the best part of the lens is used, the part with the least aberrations. A narrow aperture will also be more forgiving of alignment issues; you won't have to worry about only part of the film being in focus.
Creating an even light source is more difficult. Basically you want an even spread with no textures. I bought a flat sheet of milk-glass like material from a craft store and probably spent more that I should have. I'd start with a sheet of printer/copier paper, you might be able to fold it and get a more even spread, frosted glass might work. You'll have to experiment with the distance to the film and the aperture of the lens to not get the paper texture in your prints.
As for light sources, I would suggest anything cold, like fluorescent or led, but never tungsten. There are too many flammable materials you'll be working with, and you'll need to worry about venting the heat, etc. If you've successfully diffused the light in the last step, then it's just a matter of getting enough light through the lens so that you can expose the paper in a reasonable amount of time. Edit: I'll also add that your light source needs to be in a box so that it is only illuminating the film, not the rest of the room.
A horizontal enlarger is the way to go. A lot of the complexity of manufactured enlargers comes from being able to adjust them vertically, when you could just be moving things back and forth on a table and projecting on a wall.
Finally, and this is true for cameras as well as enlargers, the expense and value of manufactured devices is that they are accurate, expandable, modular, and versatile. You need none of these things. It's not too different in principle to a box camera. If you know how to use them, and in what circumstances they work best, then you can get great results out of them.
Since you're just getting started, just have fun. Too many people worry about all of the little details instead of just creating. I swear there's a contingent that wants there to be a high-priced buy-in to this hobby. The fact is, you can produce great work with the minimum of equipment. Photography is about ideas first. Even Miroslav Tichy is esteemed by many, and I can guarantee that you'll have to try very hard to make enlargements as poorly made as his, even with the worst equipment.