It's great to know about your interest in agribusiness. Do keep it alive.
Greenhouse agriculture is quite technical and I suppose you would be needing an indepth knowledge about it's practice before venturing into it.
Basically, you can kick start your enterprise by learning about the Global Good Agricultural Practice that ensures sustainable production. This you can access by getting a degree in agriculture or acquiring an online certification in agribusiness management as well as attending symposium that brings agribusiness practitioners and enthusiasts (like yourself) together in a room.
Likewise, I will advice that you volunteer or intern at any greenhouse outfit in your community as well as maintain a garden of your own in your yard.
You can search for Aero Farms (US) and Naturefresh Farms (Canada) online. Follow their updates for necessary tips on innovative ideas engaged in production and you could also avail yourself of their community outreach program which comes up from time to time.
Do keep the interest alive and grow your passion into the enterprise of your dream.