I need training tips, asap

I have a goal that I honestly just want to get done with the soonest I can.

a new guy entered my school and he's known for 2 things - being a sexual harasser and his harsh political views of fucking Nazism.  I need to beat the shit out of him.

what's the best way I can train at home to do that? my boyfriend taught me stances and the easiest ways for me to attack him upfront, but I need at least a bit of muscle y'know?

I don't have any money for a gym, so I came here to know if any of y'all could help me to form a routine. I am around 5'2" or 5'3" and the guy is about my height too, really thin, I weight 55kg.