Hi, is it worth to play Witcher 3, without touching Witcher 1 and 2? Is it neccesary to know the lore to play, or it doesn't matter, and I don't need to read it :D

It is possible, and an lot of things will be explained, but you will miss some hints to previous things that happened, and you won't recognize some characters. Playing the previous games adds some fun to TW3 because you better understand what's going on, but it is not game braking or story braking if you did not have played previous games.

That said - I personally am glad I played TW1 and TW2 before, and if you can afford it (the games are not that expensive) I can recommend it playing them. Keep in mind they are older games, and especially the first version has an very different play style, and an slow start.