There isn't much I can offer other than some tidbits of advice (I'm not a professional). When you structure a run, you wanna map out periods of exertion and cool downs. If you can only run twice a week, you should try to make the most of them, like, make them a decent distance or set a good amount of time. It's a good idea to slowly ramp up the intensity, hold it for a while, and then slowly bring it back down. A good scale to use, which I found on the web is:

How hard you're working on a scale of 1 (sitting) to 10 (sprinting).

RPE 4 to 5: Easy; you can talk with little effort.
RPE 6 to 7: Moderate; you can talk, but you're slightly breathless.
RPE 8 to 10: Hard; you can only speak a few words as you run.

Be sure to wear light clothes, but appropriate clothes for the weather and how intense your run is. A good pair of running shoes and a water bottle are basically a must.

As for being small and under weight, you should consider your diet. I don't know much about diets, so I can't really suggest anything there, other than that you eat what you can to gain a little weight (Even then, I'm not sure that's sound advice, take my words with a large helping of salt). Either way, you should do some light lifting. You don't need to buff up, but it is a good idea to get some muscle going.

There isn't much more I can offer, really. I hope I was able to help, even a tiny bit.

Good luck.

thanks! yeah i actually used to be into sports in like middle school so i know Technically what i Should do but >>
it’s hard to plan a regimen for myself without going easy on future me...
that’s good tips tho!

and yeah sadly there’s not much i can do when it comes to diet or any exercises that need props bc of my job that takes all my time (it’s live-in and i’m not allowed to leave the perimeters so.. it’s just running...)

thanks tho dude! i’ll do my best !!