makedonics

hy there i`m a new player from Romania,i play on the EU server, i haven`t play wot or woa, i just started playing this wow 1 week ago i`m at level 15 i don`t know if this progress it`s ok, sorry about my english, maybe not so good, i play only in co-op battle`s until 2 days ago when i discover random battle`s ...i see this kind of battle`s give more xp and more credits..i play with a battle ship, texas tier V and ussualy i play with premium ships...if you can assist me further, what premium ships is better to buy, where can i get more xp and credits, i also have ranked battle and team battle but they appear me with grey colour, i`m a huge noob at this game and i need your help..thanks in advance for everyone is wiling to help me..sorry again for my english.. P.S: when a ship became elite ship i have almost 20.000 xp with carolina ship and i can`t convert into free xp because carolina isn`t elite..thanks everyone P.S.S: i made 2 or 3 years ago a wot account but i leave it behind because the game wasn`t working corectly from my pc