I just got a new bike and the chain isn't on the right gear. I tried shifting it all the way down to 7 and then back up but it only goes to third gear even after going to second and then first. I read the manual but I'm a bike noob. Anybody know what's wrong? This is the bike I got. (I know since 99% of the people on here are enthusiasts and probably cringe at Walmart bikes but I like this one and it was cheap). 26" Men's Kent Bayside Cruiser Bike - Walmart.com