Whatever you do, you do not want to buy a 1052E instead of a 1054Z. There is a huge tech difference between these two scopes and the ~60€ price difference does not justify buying the 1052E imho. Especially since you can "upgrade" the 1054Z to 100 MHz easily and get all the other goodies in the process, too.
4 channels are a very useful tool, even if you do not need them right away. You could, for example, use the scope for some small scale logic analysis. Or probe analog cicuits where you want to see input, output and some signals in the actual circuit.
A 2 channel can do the job, too. But it may require some thinking outside the box and sometimes a pretty deep understanding of whats going on. Take the logic analysis example: Your SPI bus is acting up and you want to know whats going on. A 4 channel scope can display clock and data and chip select lines. Thats all you need to find the problem.
On a 2 channel scope you can only see 2 of these signals and that means that you miss important data. You can, of course, probe the signals one after another and try to figure out where the problem is. And it will work eventually. But seeing all signals in question at once and how they are related will make it much easier as you can not only see the signals themselves but also their timing.
As you are a beginner, Id seriously recommend going for the 4 channels, you will not regret it.
//edit: The 1054Z has much more memory and a serial decode option. Thats worth considering, too!
-phil