you must do a classic bloodwork and with your hormones (e2, lh, fsh….) to have your natty values.
And if you have a good level with several years of training and a good lifestyle you can start at 300mg/week with 3 injections per week if you take testosterone E or C.
Then a bloodwork after 4-6 weeks to adjust the doses and see if you need an AI.
You can go up to 500mg if all goes well.