Complete beginner with a lot of questions - is 23 too young to start?

[MunichMarc]

I am 23 years old and have been training for 2 years. I read that you should train naturally until 25 minimum but I see many guys online who started younger. My testosterone is 480 ng/dl from a blood test last month. I want to understand, is this considered low for my age? Should I wait? And if I do start what is the most sensible first cycle? I have done a lot of research but there is so much conflicting information.