unknown who tends to overcall

If thats a statement you are 90% sure and confident about it, then doesn't make sense to be bluffing a lot. Just valuebet more(start to put big sizes too) and bluff less, that's a good exploit vs players with those tendencies.

Probably, the best skill you can learn, is to value bet very well against selected opponents. If villains don't fold much, there's no point in finding marginal spots to bluff. It's way better to focus on value bet relentlessly.

My advice would be to learn to play tighter and for value on those stakes. When your ranges are correct, you will have tons of value to bet with(you have tons of thin value against calling stations) and showdown value to utilize and you won't need many bluffs in the first place. You have to be vary that playing too loose aggressive at those stakes can be a losing style due to rake impact.

So, first, make sure your base value game is very solid. After that, you will start to learn what spots, what boards and which players tend to fold in a given situation. Then, you can start exploiting certain spots, but know that you have to careful with choosing them as it can easily lead to you spewing unnecessary chips.

And lastly, don't try to learn from high stakes videos because players there will use principles that you can't yet understand(a lot of moves there come from lots of background knowledge and meta game that you will misuse if you try to apply) and they also quite likely wouldn't work on your stakes. Make your base game strong and build on that step after step and don't rush to crazy bluffing techniques.