@kabirinstocks Capital size is upto your capability and bearable risk. While learning, small shares is the key and increase the size gradually per your trade journal and psychology management.
A screenshot from my course slides. Since I am not able to explain verbally, I am trying to explain in a picture. I think it'll make you understand the concept in simple way.
Only practice of those knowledge will take more than years. That won't be enough. So, start practicing in live market with 1k in live market. Never do demo accounts.