There are better and smarter options for someone your age. I would go with something like Ostarine and GW if you want to go the SARMs route. That would be a far safer option.
I would start out even at one or two IU's per day. See how you like that. Then you can transition and start using three to four IU's and then go from there.
At the end of the day you need to be getting blood work if you're going to do self TRT. You need to make sure your kidneys and your organs, especially your heart, are not being strained.
We all agree that tren is the GOAT but make sure you use n2guard with it and make sure you stack it with something mild. Do not run a lot of testosterone with it. You'll get a lot of side effects.