Thanks for your prompt response, I was thinking of buying an Alambra II, since it has easy-to-learn graphic software and is opensource, I'll go for another board.
Forget about all that graphic software. For any serious design you will need to write HDL code.
Agreed.
Other than that, how can we answer the OP's question without knowing what they actually want to learn and what their current knowledge is.
If they are absolute beginners with digital design and HDLs, my own advice would be to start with a very simple board and a small FPGA. It's more than enough to learn the basics, it's cheaper, and it's usually easier to grasp. In that regard, Lattice parts are IMHO great. Other than the iCE40 series, the MachXO2/3 are great little FPGAs for learning purposes.
Once you have learned the basics and need something beefier, then you can move up to more powerful FPGAs. Xilinx Spartan 7/Artix 7 come to mind for instance.
This is my opinion. I know some people will suggest going for a beefy dev board right from the start, just because it won't limit you. It's not just the way I see how one should learn. Don't be tempted to go for complex designs right from the start. You would likely end up giving up, and even if you manage to implement working stuff with some point-and-click software tool, you will overlook the basics and won't have learned much in the end.