Help! Looking for a new method

Ive been using the patch but it turns out im allergic to the adhesive and its ripping my skin off like a plaster does so i need something new. Im thinking like the ring or cap or similar but im scared. I would have no idea whether it was in the right place and ive never used a tampon, just pads so id have no idea where to start. Also how do i know when im touching my cervix? Can anyone tell me just how id get the ring or cap in the right place knowingly?