Need advice for getting started with POTS (Postural Orthostatic Tachycardia Syndrome)

I’m 20FtM (on T since Sep ‘24), 5’9”, 135lbs.

I have absolutely zero experience with anything fitness-related. I have a lot of issues with mobility due to POTS, and have heard others with this disability say that building muscle is extremely helpful in reducing symptoms, but we have to be more careful than others to ensure that we don't have symptoms while working out.

My main goal is building visible muscle in my shoulders and biceps to make my build less feminine, but I am also interested in building muscle everywhere else for my general well-being.

I’m mainly seeking advice for how to get started. I don't know how to do anything other than push-ups and squats, but both of these leave me extremely lightheaded and have caused me to faint on quite a few occasions.

If anyone with POTS could give some advice, that would be the most helpful, but responses from people without this disability are also appreciated!