@Tatum6 Being a fast learner and being organized are definitely good skills to be a co-host, but the vast majority of hosts would not want someone to "practice" co-hosting by managing their listing.
What people look for in a co-host is someone with experience, either from hosting their own Airbnb (and having great reviews) or showing some experience in the hospitality industry.
So you could take some courses in the hospitality field, or get a job at a resort or something like that to gain and show that you have experience or training. Or host a private room in your own home for awhile if that's possible.