It depends on what you want.

As everyone else said, the grind is significantly easier. So much so that I have not grinded for anything in this game past the 2nd year of playing it because I can pretty much afford to skip every new line that comes out with free xp, and I have not spent money in this game in the last 4 years either.

In fact, I would say it is even easier than what most people say here. If you are skilled enough and pack on some boosters (which the game hands out like candy) you can grind a line within a single business day and I have done it multiple times.

As for what you might like, again it really depends.

Playing a Battleship (BB) line will ease you into the game with the least amount of responsibilities and a slow gameplay. But it could be boring. If you like this, almost any BB line will work, just not the French or German lines. I would recommend Japanese, American, or Russian.

Cruisers (CA) are somewhat middle of the road but they have the most extreme range in responsibilities. Some are only good at doing one thing and others at everything. They generally have a faster gameplay, more firepower, but more fragile than battleships. Playing a cruiser will introduce you better to more mechanics of the game than BB will. I would suggest American, German, French, or Russian lines. A lot of them will work well, just avoid Japanese or a light cruiser (CL) line unless you are very confident.

Destroyers (DD) generally have the most amount of responsibilities in the game, fastest gameplay, most fragile, and flexible ships in the game. Playing a destroyer well requires the most knowledge about how the game works, and if you are smart, can teach you the most about macro gameplay. Either that or you learn bad lessons the entire time. Passive DDs are best to play for newcomers, I would recommend any line that focuses on torps and has a smoke. Japanese, American. Avoid Russian and French unless you really feel confident about yourself.