M3000

So I just bought a Stoeger m3000. Forgive my ignorance. I loaded the shotgun at the range. And hit the button that feeds a round. And proceeded to fire. The next round did not feed into my semi auto mode. what am I missing. The ramp also gives me issues when I’m trying to load the tube. Until I press every button possible. I know it’s ignorance on my part. Never had a semi auto shotgun. Any help would be grateful. Thank u