First Time Insertion - Tips?

I just recently lost my virginity and have not been able to have penetrative sex due to pain. I’ve only tried twice but the pressure and pain was so bad that I was not able to finish the intercourse. I’ve been told that it’s likely due to my hymen not being fully ruptured, so I want to see if I can get the groove of penetrative sex via masturbation. Any tips for inserting toys during masturbation? I use a vibrating dildo (currently use it as a clitoral vibrator because inserting it scares me)