Alright Stupid Question: Tampons? Please Help.

How the hell do you put one in? Every time that I’ve tried a tampon on my period, it’s really weird feeling going in and occasionally hurts. When it’s “in” I feel like I can’t sit or bend at all. I’ve tried to look it up and places say to try to push it further but it just seems like my body rejects it, pushing it back out until i give up and pull it out (with some discomfort). Obviously I’m doing something wrong but I want to start using tampons because they ~seem~ so much more convenient for exercising. I’m 18 and a virgin and I just don’t know what tf I’m doing basically. This is so stupid but it’s a real and embarrassing struggle. Anything helps.