I was wondering how reasonable this would be, or if it would be dangerous and I should just practice regular pranayama.
My idea is to just take time out of my day(10 mins to start and work my way up to multiple hours) to meditate and focus on breathing in a way that is comfortable. First I'd focus on fully inhaling and exhaling without strain, without using breathing muscles, and without pain. Then id focus on fixing my sitting form until i can maximally inhale and exhale. After im able to sit for 30mins-an hour with comfort and perfect breathing, id focus on feeling the breath within my body.
First id focus on the feeling of my lungs inflating and deflating, then id move my focus to my organs and see how they react and feel, then to my entire body as a whole and feel each and every cell fill with oxygen and energy. Then after i can consciously feel the energy I'd start to introduce different techniques (ie. breathing in through one nostril, alternative nostril breathing, faster paced breath, slower paced breath, shallow breaths, ect.)

I know it would probably be easier to just focus on pranayama but i dont have a teacher nor the money to afford one and I feel like this would give me a greater understanding of my breathing and energy.

but what are your guys opinions on this, is it stupid and a waste of time or is it something that could benefit me in the future? thank you fou reading this and i look forward to your input and the discussions!

This is okay and can actually get you in a trance. As long as you're not straining for breath it's all good.

Don't replace the breathing exercises on the JoS fully either. Those are very important.