Can’t insert a tampon?

I have always used pads because I was kinda afraid of tampons. But now that I’m older, I don’t like how pads feel and they’re uncomfortable for me, so I really want to start using tampons. But every time I’ve tried to put one in, even when I find where it’s supposed to go, I can’t push it in. Like it won’t go. I tried with the “s” small size and a regular size, but had the same problem with both. Would it work if I found the extremely slender size ones? Should I just take it out of the plastic and try putting in the cotton part without the applicator?