(nta btw) A bb cream isn't going to cover up scars generally, they're closer to a tinted moisturizer. They may provide coverage for small blemishes and even out unevenskintone, especially asian/korean ones (as opposed to western ones) but don't expect full coverage of severe acne scars, they're not made for that.
A better option would be concealer, they're made for spot-concealing. But foundations, bbcreams and concealers are always tough no matter. Remember that if you have trouble making the one you bought work for you. I can guarantee you that the women you know who wear foundation have bought countless of products in the past that didn't work or match them.
>I also tried powdering and concealer after that
In that order, powdering then concealer? You should never apply creams or liquids on top of powder. There's a transulcent face powder in your list, you use that as a final step (if you want) to set your foundation (not sure if they're necerssary for bb cream honestly), but a translucent one won't provide more coverage.
>Why not a powder blush?
Powder generally accentuates texture. A liquid or cream blush tends to be more natural. That's not to say you can't use the one you already bought.
I say just ditch that for now and start with 3-4 of the easiest things, when you get used to that you can move on to harder things like eyelasehs and eyeshadow. Tbh I'd start with these things: mascara (easy), brow pencil (filling in sparse brown makes a lot of difference), blush (should be easy enough to master). Maybe the bb-cream if you feel comfortable with that.