My tip is to use regular size (depending on your flow) and a plastic insert with extend push. It took me 2-3 periods to figure out how to use it believe it or not. Good luck!
Depending on how heavy your period is, I was start out with a regular sized tampon and work your way up if need be. Tampons are like my best friend now! I used to only wear pads and it got quite annoying and very messy, but tampons saved the time and hassle. I'm the beginning you will feel uncomfortable, but after awhile you don't even know it's in there. If you have the tampon in and it hurts, you should take it out and try again. I hope this helps you!