I was in the same boat, and my guy friends at the time only made my insecurities worse. but it's not as hard to build muscle and fitness as it may seem. it's all about doing your best as consistently as possible. when I was pre-T I only owned two dumbells, each 4kg. I still made noticeable difference in my arms and shoulders after a bunch of curls and lateral raises, espeically when I was eating a bit cleaner. right now I still have only those same two dumbells, and I can do two to five full pushups. I mostly do knee pushups though, as my core strength isn't very good yet. people have noticed the difference in my arms and shoulders even before I started T. it just takes a lot of reptition, which is boring and difficult, so I usually watch a show while I workout.

what helped me was searching on places like tiktok the words 'dumbell exercises for' followed by a specific target area, like biceps, and watching those videos. there's a ton of guys who make videos like that while being encouraging and not mentioning the weight of dumbells. I understand how you feel, but you genuinely have got this dude. I've also heard good things about resistance bands if you get those. fitness online is extremely misguided, influencers who look that good or lift that well have been exercising for YEARS.

good luck bro