Well when I started you could walk into any supplement shop and grab superdrol, hdrol, M1t, etc off the shelf so around 2 years.
The most common answer I’ve seen is to wait until you’ve reached your natural peak. I don’t think it’s necessary and I truly don’t think too many people even know what their complete natural potential is. I’d say get a good few years of training and dieting consistently and correctly. Really learning how to properly push, train hard and knowing your body and building a decent base. Do your research so you’re not on a board asking for help and wondering why you can’t get an erection or you’re lactating. I’d also say wait until you’re financially able. You shouldn’t have to decide between buying a bottle of test, affording food and paying your bills. I’d also add in if you can’t afford blood work then you can’t afford a cycle but that’s my opinion.