How to repair a push lawn mower?

I have a Craftsman push lawn mower that I purchased used last year. The lawn mower ran fine almost all summer last year. I tried to start the lawn mower yesterday and it did start up. But there was a lot of blue smoke coming out. The lawn mower did cut a little bit of gr. Then it shut down and would not start back up. It has a new spark plug, blade, and filter. The oil was drained and the gas was drained last year. Due to the gas getting mixed with the oil. Not the two mixed together in the same tank. It all happened when I tilted the lawn mower up on its front tires. So how do I fix this issue so that I can get my lawn mower back running again? Also where is the Carburetor located at?