I guess I started with tractors on my grandparent's farms. They were manual but of course you didn't shift once you got moving. They had clutches but you put them in the gear that you wanted before you started moving. They were not synchronized, at least their old tractors weren't.
First true manual that I had to shift once I got moving was my first motorcycle. A Honda S90. I think it was a 1965 model. I bought it from the grandfather of a friend and my mom dropped me off to pick it up. I figured it out and learned to shift it on the way home. I had never ridden a motorcycle before, maybe a mini bike or two owned by various friends.
My first car was an old 1959 Chevy Belaire that my dad gave me. It had been his work car. Wish I had it back now. It was a two door with a six cylinder, probably a 235, and three on the column. Drove the wheels off that thing. Have owned many manual models over the years. Cars and trucks. I still enjoy driving them but it's been quite a few years since we owned one. The last I remember was a Honda Prelude with a 5 speed that I had bought for my wife just before moving to Ohio about 17 years ago. She actually loved that little car and drove it to Ohio when we moved.