I bought my bike from Walmart (first mistake lol) during my first ride on the bike a bolt fell off and the line that leads to the shifter flayled from its holding. I have never dealt with this kind of problem before but being the macguever I am I attempted to fix it. I found a bolt to fit it and wrapped the line and bolted it in place. The bike functions now but won't shift gears. Occasionally while riding it, it will make a click and the pedal will fall quick making it hard to keep balance on the bike. I think I didn't wrap the wire tight enough but I need help, how do I fix this? What exactly did I do wrong? And thanks guys!
1st post some pictures of what it now looks like.
Then we can tell you how to fix it - maybe.
Have you looked at: "How to install a rear derailleur" and "How to adjust your rear derailleur" above? If not do so.
Much too little info in order to tell what's wrong, let alone how to fix it. Unless you assembled it yourself there is no way that any part should fall off at all, let alone in the first day. If you are now missing a part repair will be very difficult. My first advice would be to return it if they assembled it and insist that every part and adjustment be fixed. If you don't want to do that or you assembled it then either take it to a real bike shop (expense), find a knowledgeable friend or go to a bike co-op. Last choice (because in-person assistance is always best) is to look at the tutorials here and the ones you find with a Google search for "adjust derailleur." Look at several before you try to fix the problem, and study the ones in writing first - videos sometimes leave out important info). sheldonbrown.com and parktool.com are two of the best sites.