Firstly, welcome to the game, great to have you on board. Corregidor is a really popular sectorial with loads of good options.
5 man Alguaciles link is a great backbone, so I would suggest the vanilla Nomad starter plus the 4 man Alguaciles special weapons box.
One really strong tactic is dropping smoke in front of a model with MSV2 that can see through it, with Jaguars the go-to option for smoke shenanigans, and you can proxy your combi-rifle Intruder as an HMG
Moran Masaais are great options too, with their Crazy Koalas able to lock down whole sections of the board.
Finally, one of the best things about this game is that nearly every option is viable, so I would suggest having a look at which models float your boat, throwing a few lists together in Army, and making your choices based upon that. You'll end up buying everything in the end anyway