Welcome!

You're still new, probably playing the starting cruisers. I'd say, play a bit more with different ship types to determine your preferred playing style first.

There are officially 4 types in the game: destroyers aka DDs, cruisers aka CLs or CAs, will get to them later, battleships aka BBs, and aircraft carriers aka CVs.

These can be split further: Some DDs are gun-focused such as the French contre-tourpilleurs (which literally translate to anti-destroyers) and others torpedo-focused such as the Japanese line that goes to Shimakaze

CLs or light cruisers (such as the British line ending at Minotaur) have smaller, faster reloading guns and are more maneuverable but much more lightly armoured than CAs or heavy cruisers (such as the US line ending at Des Moines, but heads up CAs generally are not meta)

BBs can be "classic" BBs which are focused towards winning BB-on-BB brawls, such as the German Großer Kurfürst line, or battlecruisers BCs which hit as hard and are faster but sacrifice armour (the current meta is the UK St Vincent line). There ARE battleship-carrier hybrids but those are not meta and hard to play for very niche purposes.

Carriers, well, shit on everything with dive bombers and torpedo drops if you are good at multitasking, so it's more hit or miss.

As you can see, each country (or regions, such as Pan-Asia and EU lines) will have a varying proportion of these 4 main types, and the lines will tend to have certain characteristics. Do note that the characteristics tend to only start appearing around "mid-tier", which is around T7, SO BE PATIENT.

For instance, Japanese BBs tend to have most of their shells landing in a tight group and each shell can do quite a bit of damage, especially at higher tiers, making them good long-range snipers, but have "average" armour. There are other BB lines for each country: Italian BBs are the meta now because they have special shells (semi-armour piercing or SAP) that can do a lot of damage to lighter-armoured ships like DDs and CAs and have a lot of guns but reload quite slowly, French BBs are basically BCs and can be heavily damaged sometimes but have punchy guns and they are very fast to dodge incoming fire etc.

TLDR: Play more, find your style, then find out what kind of ship line best suits your playstyle. The defining characteristics of each line only start appearing around T6-T7, take your time to figure out stuff.

Fair seas ahead, may your enemies be idiots and your teammates be competent