First time posting here for bikes. I have an old wally world free xr-150. It was my favorite bike as a kid when it was all about fun. It's been sitting around for many years. No real rust or tarnish. I know its not a posh riding bike, however I like it and don't feel like buying a new one. That being said it needs a new chain as far as I can tell, as one of the links are rusted. I won't know much else until I got out and take it for a spin. Without a manual I'm going with experience and dumb luck figuring out what it needs. Anyone have any info as to anything specific I need chain wise? Was just going to buy a multi-speed chain of the correct length for a replacement.
Also, any immediate things I should upgrade? Like I said as a kid it never presented me with any issues, broken parts, etc. Maybe one of the few non-lemons out there. Just looking forward to keeping it in shape and many more years of use. I know there are a lot of new parts out there and just trying to wrap my head around what I should upgrade it with and why.