Im a new player myself (3 days old (and a 5 yo wot player)). Ive wasted two of those days playing against bots lol. Nvm carry on.
Curently, im dedicated to US tech tree. If you feel too slow as i did, go for t4 Phoenix and t5 Omaha. Having extreme fun with the latter. US DD`s im not too keen on 5km range torpedoes early on. On your way up, u will have to manage through St. Louis (22 knt top speed), but any higher than that you wont gonna sail slower than 32 knts.
And as far as ive seen, Cleaveland is something to look for. OP anti - air capability, spammy 4 x 3 152 mm guns, great speed and above avg. mobility. Seems like a moneymaking keeper for me.
For DD`s im having a blast with Umikaze (t2 IJN), sealclubbing those newcomer BB`s, torps are kinda slow, but with that reload speed, things simply cant escape you. And with 5.6 km visibility vs 8 km torp range you can train some mad skills with complete impunity.