"There are so many DJ mixers out there on the market. It depends on what you're looking for, you have the standard 4 channel mixer and then you also have the 2 channel mixers. You can get a 2 channel mixer like this one, this is a Ring TTM 57.
I would start with research, asking a lot of questions. Ask yourself do you want a basic, beginner mixer or do you want something more special? You don't want to just go by price because if you buy a real cheap mixer for like 100 dollars, you know sometimes it's true you get what you pay for.
Also don't go by the most expensive price, just because it's super expensive doesn't necessarily mean it's good for you, it might be too much. Go by the descriptions, by the brand also you can try to see if there is any aux in's? Does it have any built in effects? Sometimes that might determine if you're going to buy the mixer or not. Most mixers don't come with any sound effects or anything fancy. It's just a mixer, where it receives signal and it sends out signal.
But then there's other mixers, like this mixer, where Salano will be built in, so there's a USB port and Salano is built in and just plug and play. You can get a good mixer for a decent price within like the 1 to 300 dollar range, to start out. But, like I said, it definitely requires a lot of research. I personally use Ring products, especially with the TTM 57, it's perfect for parties, events, touring because Salano's already built in, so like I said I just turn on the mixer, turn on my laptop, open up the program, connect the USB cord and I'm ready to go.