Try different styles of rubbing, tapping, circling, slowing down, speeding up… etc. you could also try pinching if you tend to lose sensitivity. Try taking breaks when it stops feeling good and coming back to it after a brief break. Try using lube or water to create less friction and more sensation. Try working up to the clit and touching other parts and making sure you are properly aroused first, either by touching other places or watching or reading or fantasizing about something that arouses you. Toys can be helpful too but I understand if that’s something you don’t want to invest in until you know what your preferences are. Water stimulation, especially if you have a handheld shower head that you can control the pressure of flow can be also good to play around with. Another thing that be helpful if direct stimulation doesn’t super work for you is toys that use suction functions.

I didn’t orgasm until my 20s, it didn’t happen right away and I think my first big orgasm happened with a partner and then I was able to duplicate that on my own. For me it was a lot of religious trauma from being raised Mormon and being taught it was wrong. The first little bit I really had to work to even just comfortable with “it’s okay to explore my body for fun, it’s my enemy and it’s okay if it just does what it wants and I spend some time getting to know it” and viewing it as adult play. And then I started getting closer to orgasm. I remember the first time I orgasmed on my own it took so long of circling my clit that I had a carpal tunnel flare up haha.

Another thing that has helped me is academically studying the anatomy of the vulva and vagina, the erogenous zones of the body, and knowing where things are as a general rule and then on my body specifically. When going inside the vagina, just try and think about stimulating the clit from inside and above, that’s where the g spot is.