I would probably go down the route that most Marinas do. A simple tree style rack.
Design like this but home built or just find a cheaper one.
https://www.logkayakrack.com/product...-storage-rack/
Not sure where you live or where storage would be but a freestanding rack would just be asking for theft in Los Angeles. Would need to be pretty tucked into the complex or in a shed or something.