Not all people with prostates enjoy having it stimulated.
Like the g-spot, or any other part of the body, some people will find stimulation arousing, some will find it boring, some may find it painful.
Unless the scientific approach is a turn on for you, trying to find the prostate in a dispassionate way is neither the best nor more enjoyable approach.
If you are exploring on your own, find a sex position you are most comfortable in where you have access to your bum. Sitting in a comfy chair might work, or lie on your back with your legs in the air.
You can use conscious breathing techniques to deepen your awareness of physical responses.
The prostate gland is in the middle of the pelvis and produces part of the fluid (called seminal fluid) that comes out when a man ejaculates.
You can't touch the prostate directly, but it is possible to stimulate it indirectly, internally via anal stimulation and externally by applying pressure on the perineum.
It also helps to relax, which is an important state to be in for any sex play.
A bath or shower can also be a great place to explore your own or your partner's body.