yes thank you all for your advice, on the third try i barely managed to land and i did a little jump which made my lander spin and crash (all kerbals are alive, well...i hope so) but i just have to practice and figure out where to start the engines to save deltav but still make a safe landing. There is only one other unknown: if I will be able to go back to Kerbin, the DeltaV is super tight and the image is very, very small, so if you can recommend an engine for this situation, that would be nice.