The game is pretty much the same. Qo'nos takes some getting used to, but beyond that, the game play is largely the same. All you have to do is learn how the ships handle, which if you've leveled several Feds, should be no issue. The KDF has a lot less missions though, so you grind the nebulas and star clusters since low level PVP is very rare.
If there's more specific questions then ask them, of course.
I doubt there is a guide to cloak use. The basic tactic is simple, really, you use it to get close to an enemy then decloak and unload on them.
The mechanics to it are as follows:
Stealth rating improves with aux power, and skills invested in starship engineering training, aux maintenance, and aux performance. Its not really useful to shunt power to aux to improve cloak, however.
After decloaking, you get 5s of a 15% damage bonus, so make it count.
Cloaking lasts indefinitely, and after decloaking, there is a 20s cooldown before you can use it again.
Battlecloak is only available on BOPs which means their cloak can go up under attack, and will stay up if they get attacked while cloaked.
If you're too close, the enemy can detect you and attack you. There is no way to tell how close is too close.
There are several powers that will forcibly remove cloak, like eject warp plasma, tractor beam and charged particle burst.
Most any finer points come with experience, of course.
Concerning Cloak: I believe effective range to decloak is around 5km, since at that range, all weapons deal good damage. And you can't usually get much closer before getting detected.
Actually you can get much closer. Science ships probably won't detect you until 3-4km, maybe. And of course you can always get closer while they have their attention elsewhere, even if they should see you, they still may not be aware. They can't afford to run a full sensor setup because its a waste.
For anything else, you can easily get within 2km undetected. The thing is though, inside 5km you are in the danger zone. CPB and sensor scan have a 5km range, and if you get hit with those, you're spotted and decloaked.
Of course it varies with your skills and their skills, nothing is certain. Personally, though, I decloak around 2km against non-science ships when I'm ready to strike with my raptor.
With battle cloak you need to remember that you are without shields for the few seconds you are cloaking back up after a strike and you will be vunerable to kinetic attacks.
So don't wait until 10% hull to try and escape because you will have incoming torps on your backside. And they will follow you for a ways.
I learned the hard way about this one.
If you stick with the BoP's after Lieutenant levels, using Resist powers is a good idea just before you go into Battle Cloak if you are currently under fire. Polarize Hull and maybe something else so that the hits you do take on your hull hurt less. Nothing worse then having 100% hull and getting critted by a Quantum Torp Salvo that hits at -just the wrong time-.