tampons for the first time

Hey guys, so I'm on the second day of my period and I just put in a tampon for the first time. I've have my period for about two years and I've never really needed them until now. My mom doesn't use them so she isn't really helpful with them, so I just have a couple questions. Should I be able to feel it? I feel it a little bit and it feels weird but I'm rationalizing this with it expanding. Is that right? Also how long should I keep it in for? The box says 8 hours but I'd honestly really like some advice from actual people. Thanks!