I've played it a lot at my local game store. Going off the top of my head...

You can have 3-10 guys in a kill team. One leader and one only. Only half the models can be recruits. You can have up to 3 specialists (normally 2 for most factions).

-Vet sergeants are your leaders -Vet guardsmen are your main troopers -Guardsmen are your recruits -Special weapons guys are specialists

All your guys are BS 4 except for guardsmen which are 3. Specialists can take main guard special weapons like grenade launchers, flamers, heavy flamers, snipers, melta guns, and plasma guns.

Lasguns are the bread and butter weapons. They are still kind of weak like in normal 40k but are very reliable with an ammo check of only 3+.

Snipers can take toxic rounds for their rifles which makes them AUTO WOUND and the injured person rolls on a separate injury chart when hit by them.

There are also 3 sub-factions that your kill team can have. They are cadians, catachan, and steel legion. The only difference between the sub-factions are the skills the guys can have.

Your leader has the 'Voice of Command' special rule. This allows the leader to forgo his shooting attack but lets all allies within 6" of him to re-roll 1's when shooting. Pair this with snipers who have red dot laser sights to have them hit on a 1+ (yes 1's always fail but it you can re roll 1's if a guy is in the open).

Thats all there is really, besides some extra gear and some weapons that can be taken. They are a shooty army that can hold down points pretty well, especially if you take 3 grenade launchers. They can pin entire armies in one turn (but they are expensive as hell).

I cant give you point values as per subreddit rules, but dont worry, they arent as expensive as other armies.