Im sick of being shy, introverted. I want to be kore assertive and good at convo

TLDR at bottom

Im shy/timid and am so accepting of other people’s life. (“Oh u like that? Cool” “oh u wanna do that? Sure whatever rolls with u, who am i to judge”) I dont like “attacking” other people’s beliefs, or make sarcastic “jokes” about them for being who they are, or point out their flaws because i believe no one’s perfect and we all have our flaws and insecurities.

But this accepting nature of mine is a big downside (+ shyness + social anxiety) because i come off as easy target for my friends to make fun of.

One of my buddies, lets call him guyA, he is a big entitled hypocrite and has many many flaws. But my friends dont call him out on it! They might mention it a little when he’s not around but they can never say it to his face. I think its because they know he’s narcissistic and is too stubborn to sway from his own opinion.

i cant stand up for myself when i need to, because i cant come up with conebacks on the spot. I think about the perfect comeback like 5 mins later and if i do manage to stand my ground they call me stubborn and tell me to “stop arguing all the time” But when guyA stands his ground no one bats an eye or bothers correcting him.

And to make it worse, if guysA puts me down (which he does often) then other friends join the bandwagon and start “attacking” me as well.

Just recently started to realize that he has been manipulating, gaslighting me and others. Making me feel guilty about not catering to his demands. He twists stuff around/exaggerates/guilt trips u in front of others, making u look bad.

I dont know if he does all of this intentionally or not, because i know him and he is not a bad person at heart (morals wise) but he is a bad friend. I guess u could say he’s really street smart. Knows exactly what to say at the right time and also knows how to say. He is also assertive and is able to manipulate things his way without making other realise. He also has lots of other friends(is charming/magentic?) so its proves he had some damn good social skills

I have seen how he gets his way and i believe he will thrive anywhere because of his skills.

I dont want to be naive, nice, shy anymore. I want to be assertive AND need to learn how to be manipulative so i wont get manipulated ever again.

So please tell me how can i be more
1) persuasive
2) manipulative
3) assertive without coming off as “overreacting”
4) say right/smart things at right time
5) i want to dominate convos
6) recognize people’s ulterior motives when they are nice to me.

I NEED to get rid of the image i currently have. Please don’t give me any “oh u should not stop being nice because of some people” blah blah bs. Because if the people i call FRIENDS can hurt me in such a way, then i fear what the strangers in the world are capable of.

Also, sorry I ranted out above because i needed to get it off my chest.

TLDR: i am shy, timid, introverted gal who has social anxiety, and i want to learn how to be aseertive, manipulative, persuasive, and recognize other’s people ulterior motives and be able to handle the confrontations or any conversations, and stop being naive

Any youtube videos, books, sites? Anything