How do I get my lawnmower running?

I bought a used Weedeater push lawnmower and used it for the first time yesterday. It's been raining for a few days so the gr was a little damp but the gr was extremely long and I live next door to my landlord so i had to get it done. It turned off a few times in the really long/wet spots but I managed to get the backyard done. I moved to the front yard but when I tried to pull the cord it only pulled out a few inches, it seems like the cord is locked. This is the first mower I've owned and I know nothing about them. Someone suggested it might need oil? Also when I started it before it looked like a little smoke came out from the side. Pretty sure it's not supposed to do that.