I have pinguecula. is it okay to rub my eyes?

No: It's really not ok for anyone to rub your eyes. It's better to use artificial tears to soothe them.

Pinguecula: But not a aggressively. Lubrication would be better. A pinguecula, which is a deposit/build up on the white part of the eye (sclera) due to uv light and dryness of the eyes. You can use artificial tears, and use a cap and/or sunglasses when outdoors. If it gets large, constantly irritated (red), or grows over the cornea, you may need medicated drops or surgery.

Gently: Eye rubbing willl usually not affect pinguecula if done sparingly and gently. This rule should be followed in any case, for any decision to rub your eyes whether or not a pinfuecula is the issue.