Reading where you are currently at I'd recommend to hold off on taking AAS for now. You still have a lot of potential to go and a lot to learn about what is going to work best for you outside of a cycle. That experience and knowledge will help you while on cycle as well. That is awesome that you have been working out and sticking to your diet for a good amout of time now (6mos) but that is not nearly enough time to reach any level of genetic potentiality (that is a good thing). If you are thinking your age is a limiting factor it isnt. The desire to get big as fast as possible can be great but there is more to lifting weights than just getting big, there is the challenge everyday of sticking to the workout and diet, tracking your strength gains making sure you are hitting progressive overload - watching those numbers go up, the gym culture, et. cetera. Anyways I'll stop my rant now, typed up some notes below that might be helpful.
You can get tests done through LabCorp, they have info on their site of how to order. I suggest going to your doctor first and tell them you just want a general health check for your liver, thyroid, and sex hormone values just to make sure everything is ok. Do not tell them you plan on taking anything, keep it as a simple generalized checkup with bloodwork. That will give you a baseline and from there you can go the independent lab results route for comparison.
The thing you have to be made aware of, and is rarely discussed, is not just the physical risks and mitigation but the psychological risks. Hormones have a significant impact on a person's mental and emotional state. I'm not necessarily talking about roid rage, from what I've seen that is quite rare, it is the super high up while on and the hit of depression when you come off. It is partly due to the changes in hormone levels and compounded by the loss of most of your gains while on and if you have sides like gyno it's another layer. You might feel like a god while on; I remember my first cycle of test, every week the weights were going up on the scale and the bar. I was picking up 45's tossing them about a foot in the air grabbing them on the way down and slamming them on the bar like they was my bitch. About 3-4 weeks after the last pin though... bodyweight and strength start to drop, you might start gaining some fat, your emotions are out of whack and then depression about it all really sinks in, no matter how good your PCT is that is all a possibility. Some folks deal with this really well, others not so much.
I'm not trying to steer you away from AAS just want to make you aware of the mental and emotional effects that may arise. Having people you can confide in and meditation can go a long way to mitigate those states.
Some things to research:
Diet - make sure you are getting enough calories and macros are in check and be prepared to adjust during cycle and off cycle. Also remember diet is all day every day it has to be consistently done.
Water - may sound like a no brainer but I seen dudes get dehydrated drinking a gallon a day, intake needs to be pretty high
Pinning - know how to do this properly, you do not want to accidently inject into a blood vessel, the coughing will be horrendous (I know from experience)
Stock - make sure you got everything you need before starting, gear, supporting meds, PCT, syringes and pins, plan in case things go sideways, ways to bring yourself back to earth if you get in a super high or super low mental state.
The more prepared you are the more confident you'll be and the more you'll get out of the cycle.
FWIW my last cycle was over 15years ago and I still think they all would have went better if someone laid out the basics and not just dosages and what stacks best with what...