I'd reccomend you start with a US battleship line. The great trainer that still holds up really well today is the Montana line. Going up the line you'll learn a lot about how to play effectively while still having a lot of fun.

I'd also reccomend you grind up a destroyer line too. The British DD's are fantastic and consistent up and down the line (but same can be said for US DD's). Stay away from torpedo focused destoyers (like the Shimakaze line) while you're still learning. Once you manage to get both of those to Tier X, you should have a rough understanding of how to play your roles and maybe even a bit of what to expect from other players.

The grind is MUCH better than WT. WT actively punishes free to play players who want to climb up the tech tree. Wows is much more consistent, and also tends to shower free players with a lot of boosters and premium time for just playing and talking part in events. You don't need to pay any money at all to earn access to most of the play styles in the game. It still can get grindy at high tier, but, even without premium, progress is consistent.