I honestly think I'd like to work out, I've always wanted my body to look a bit leaner and meaner but I wouldn't know where to start

and the day after sore feels so amazingly good.. it's a good sore IMO.. A much different sore you get from drinking heavily the night before and waking up somewhere you don't remember walking to.. I had to help my dad deliver 3 skids of wood to a house he was working in once.. Each skid contains roughly.. 60 packs of wood, each pack weighing 53 lbs.. Sure it sucked and wasn't too fun with my puny arms but I loved the sore I had the day after.. Anyone have any advice for a youngin' looking to start working out? Should I join a gym and get a personal trainer or whatever? I always thought that was kind of expensive.. Any suggestions?