Before taking your T7/T8 ship into ranked, consider this tier list that I have made, some ships in ranked are simply out match by others.
Note that this is based on personal experience/opinion, and I will try to explain each ship. Carriers are not included due to how rare they are and in most cases, are mirrored.
Benson (Oh yes, the DD meta, who wouldnt want to use a DD that have both the RU’s stronk guns and IJNs stealth torpedo ability? That concealment is another good reason why this ship stands above the rest)
Amagi/Tirpitz (Best BBs, Amagi with best guns and Tirpitz with protected citadel)
Atago (<10km concealment, guns do reliable dmg to every ship, great torpedos, repair)
Mogami (155mm only, with DD meta the Mogami is the best CA to deal with them)
Fubuki (Lowest detection, guns are workable if you dont engage in extended combat, great torpedos)
NC (Tankiest BB and can bounce AP easily if angled. Setback of bad dispertion and weakness to HE rain makes it below the other T8 BBs)
Myoko (Worse version of Atago)
Mikhail (Worse version of Mogami)
Blys (Good guns and torps, but a T7 means it doesnt have the T8 concealment upgrade)
Kiev (Still pretty good, deal nice dmg with offensive smoke, good fire rate with shells that dont travel to space, bad concealment tho)
Nagato (Amagi is simply better, it cant compete with T8 BBs)
Admiral Hipper (Concealment is the main problem, leave killing CAs to your BBs)
Hatsuharu (Fubuki have better concealment with T8 slot, more guns and more torpedos)
Sims/Mahan (Benson have superior concealment, guns, and torpedos)
Tashkent (More hp pool, but offset by easier to hit due to size. Less range than the kiev)
Colorado (Just why? Very low health pool, bad dispertion, low speed)
New Orleans (You take an Atago, take away its strength of concealment/torpedo/repair and you got this ship)
Yorck (Easy citadels, bad concealment, sluggish movement)
Pepsicola (An afk is worth more than this ship, because an afk is usually safe in the spawn, using this ship not only contributes little to the team, but also helps out the enemy in points when an Amagi looks at it)
Atlanta (Oh I am great against DDs, lets go up there and…… I_Citadeled_UR_Ass (Amagi) “Devastating strike”)
If you are using a ship C tier and below, I recommend grinding a higher tier ship, as most of them are T7s. Whatever you do, please make sure to at least equip camo and 3+ combat signals on your ship, so that your teammates knows that you are at least serious about winning.