What banner should i pull(NA)

You mean which of the class-specified ones? 'Cause tbh if I had to say, I'd just say skip them all since there are better options (Jalter, Ishtar, Merlin, Gil, etc). If you want a lancer, why not roll Tamamo or Kiyohime right now? If you're set on the class banners though, yeah, lancers are your weakest class right now, so roll that.

Also bear in mind that we will be getting Jalter santa lily as a welfare servant for the Christmas event this year, likely in November. She is an AOE, and while she isn't the absolute best, she's pretty good. Also, your assassin lineup isn't amazing either, and the Christmas rerun comes with Jack on rate-up.

Well if you only care about gameplay lets first get Merlin out of the way save for him if you want the game to be really easy. Ok now that that's done lets look at servants that will synergize with your other servants already. First and foremost for the lancer problem you brought up I would roll the friend point gacha for cu since he's one of best simply because he doesn't die.

Also I didn't know if you were talking strictly about the classed based summoning banners and if so I would either roll for the assassin banner since you don't have a good assassin and you missed out on shiki and jack is the best assassin right now. I wouldn't roll on the lancer banner since story lancers aren't the best and cu outclasses in my opinion eli and I wouldn't waste quartz when you can get cu instead, but if you need a gold lancer wait till Christmas for the wellfare lancer.

Overall just go for servants you like still this game is no where near hard enough to where you can't beat it with supports but if you must roll go for either the lancer or assassin banner on the class specific banners or save for melin in December.

I would advise you to roll for a Lancer servant (Tamamo is really good) . Gold Lancer is a rare commodity (even worse if you get a Fionn).

Cu FSN is a good lancer but his damage output is considered very average now. He is mainly used in the backline as a last standing man.

Gameplay-wise, I wouldn't bother with Merlin and Jalter if you are a F2P. Your support list will be full of them, grailed and max skills.

There is still time for November to save for Jack.