Perforated leather jacket/pants have a bunch of tiny pin holes – if you hold it up against the light you can see light thru them. They allow a surprising amount of air movement when you’re moving. If you want leather jacket in warm weather, perhaps get a white one to reflect the heat in direct sunlight.
If it’s 90 deg or above, or muggy like in Florida, “mesh” textile jacket and pants really makes a big difference. “Mesh” means a much looser weave (bigger holes) than standard textile material, sacraficing abrasion protection, but still have paddings in elbows/shoulders/knees, and is much cooler. It almost feels like you’re wearing nothing in terms of cooling.
For boots, decide if you want water-proof (to deal with summer downpours but hotter), or ones with ventillation (cooler but may get your feet wet in the rain).
By 3-wheelers I assume you mean 3-wheel ATVs. Motorcycles have 2 wheels, which are very different in terms of steering and handling from 3-and-4-wheeled vehicles. I find bicycling experience, especially off-road mountain biking experience, very helpful when I started riding motorcycles, but it was still a steep learning curve to ride motorcycles well.