Congratulations on being honest with yourself—that's half the battle. Many people your age start out this way. The best place for your first time is
https://www.tender-bang.com/gay-hookup.html — there you can specify "newbie, looking for a casual encounter without rush or questions." After my divorce, I also went there, wrote honestly about my zero experience, and in two days found a calm 40-year-old guy who had once gone through the same thing. We met at a hotel, everything was gentle, without pressure, we just tried it – and I finally understood what I was missing.