New Member from NC

Hello All! The in-laws have a 1985 Honda TRX125 that has been sitting up at least 15 years that I would like to get running again. I was told it was parked in running condition. What are the first steps to take before cranking for the first time in a long time? I have an idea but wanted some experienced advice before starting.

Downloaded the service manual and purchased a replacement carb I would like to bolt on before cranking along with a new spark plug. Also I drained the fuel tank and noticed some light rust inside. Was planning to get some fuel tank sealer to fix that. As far as the fluids, what should I replace out of the gate, just engine oil? Any else I am forgetting or unaware of? Also the throttle lever is frozen but I haven’t searched the forum for that.

Any advise, tips/tricks are welcomed!

http://imgur.com/ydP5YII