The best clans vary from week to week depending on the bans, this week Freaks was quite strong but next week they will have 2 cards banned
from the clans you said you like to play, Montana and roots seem to be the most playable, although they both kinda lack damage but they have plenty of damage reduction
la junta is a nice clan, strong on paper but rarely used in ELO (Except this period when we have the la junta ld) they are pretty vulnerable to SOA but have plenty of damage
next week a lot of good cards will be banned, but there are clans that have all their staples, like montana, uppers etc
if you are only beginning in ELO and want a reliable deck that can work decently in any week, you can start with a mono clan like rescue, jungo, montana, sentinel even roots or piranas have some nice monoclan decks, in the end it's more about trial and error and seeing what works for you.
For one, whenever using a mono Junta deck, be sure to include Thormund, Isatis, and Chiro, they are beast.
And example mono-junta deck: Dean, Isatis, Jane Ramba, Chiro, Thormund, Ray, Trish, Wardog
For Junta/PCat mix, you could use:
Noemi, Cherry, Muze, Lucy/Brittany, Dean, Gatline, Wyre, Nahomi