How should I start?

LiannaSilverwind: I suggest upgrading your tank whenever possible, because it is much more enjoyable to play fully upgraded tank than undergunned, underpowered, slow vehicle of doom that tries to "get more xp per battle, just 30 more battles, just 29... oh damn, I'm dead once again, because I cannot do anything"...
If you are in no hurry to get tier 9/10 tank, then enjoy your path! Say No to grind, say Yes to enjoyment!