Most Klingon builds I see are based on Vor'Chas and B'Rels.These 2 ships emphasize what Klingons are best at, cheap high attack ships. For the points the Vor'Cha is one of the best ships in the game. 26pts for 5 hull and 5 attacks. It also has a very generous maneuver dial, with 6 greens on it

There is a reason why you see a lot of Enterprise Ds and Khazaras on ebay. The ship is so solid people buy multiple starter sets just for them.
The B'Rel is great because they are the cheapest ship with 4 attacks. They can be easily one shoted, but a pack them can dish out a lot of fire. The B'Rel is the best ship to build a swarm fleet around. Also the only red on its dial is the 3 come about, very maneuverable

You can only get it as one of the 2 brize ships right now. It isn't bad to own multiple
Ch'Tangs because several of it cards are not unique, Barrage of Fire, Defense Condition One, and Seconday Shield Emitters. Duplicates of all of these are good to have. The ship ability to reroll blanks when cloaked is really awsome. Skill 9 Martok is nice, but you get more out of the skill 8 version. Korog's
BoP is a good ship but there is nothing in it you need multiples of. The Klingon/Borg
BoP is too expensive for a 3 hull ship. You can put Borg Hull Armour on it, but it isn't worth slapping 10 more points on or buying a Sphere just for one cards.
I love the Neg'Var, but I find that I use the cards from it more then the ship itself. The extra hull is nice but the Vor'Cha can do just about the same job for cheaper. Martok and Gowron from this pack are must haves for a Klingon ship. Drex is the Klingons way to get battle stations. Kling on Boarding Party if fun and a lot of people don't expect it, especially those fed players with loaded ships.
The Koraga/K'Vort is a nice ship, but more than anything else you are buying this pack for Worf. Free rerolls on blanks is great

The pack also comes with N'Garen , which again is the Klingon Battle Stations. It is also a only larger Klingon ship with a rear arc, the Vor'Cha & Neg'Var do not. The Koraga is cool because it gets +1 defense when cloaked.
The K'Tingas are ok by for 2 more points you get another hull on the K'Vort. There is really nothing that is a must have in Kronos One. The B'moth is a much better ship, better ability and it has a tech slot.
K'Neras from the B'Moth is useful if your opponent is crew dependant.
If your not that into
TOS only then there isn't any must have in the Samrow or the G'Roth. Samrow has one really good card and that's Bu'kah, if you perform a green maneuver discard to repair 2 hull, but not woryh buying just for that. Koloth and Projected Stasis Field are the biggest reason to buy the G'Roth if you're not into
TOS. These ships aren't worthless, but can't stand up to the
NG era ships.
I would say the 3 must haves for Klingon beginners are the starter, Neg'Var, and Koraga. 2-3 Vor'Chas are nice, but don't drop big money on 3 starter sets just to play casually.
A good Klingon starter build is:
28 Neg'Var Class
05 Martok
05 Klingon Fleet Captain
00 In'Cha
26 Vor'Cha
03 Worf
04 Drex
24 K'Vort
04 Gowron
01 Klag
Martok is skill 10 and can shoot before most things, he passes around free actions (mostly for Gowron), and the fleet captain can let Worf use Drex every turn. It should easily throw 14-16 dice a turn, has some good action economy and doesn't require paying big money for prize ships. Great for beginners.