There are 3 main types:
Cheap (£40) look-like-a-canoe-but-made-like-a-cheap-pvc-dingy things – Advantage = cheap, disadvantage = flimsy, delicate
Fabric (cordura type) covered bladder construction like most Sevylors and the Decathlon Itwit things – Advantage = tougher, stiffer, individual bladders can be replaced if damaged (if you can find the spares), disadvantage = the fabric element is stitched, meaning eventually you are sitting in pool of water, and the fabric can be difficult and time-consuming to fully dry – mildew probable.
Hypalon/Reinforced pvc construction. Think of the material a decent WW raft is made of. Advantages = tough, with welded seams, hopefully water won’t be guaranteed to enter. Can be inflated pretty rigid. Easier to dry (can wipe dry with a towel) Disadvantages = cost, heavy, if punctured/damaged a thorough repair will be needed.
We have 2 16 foot polythene open canoes and regularly take out our 3 and 6 year olds on loch, river and overnight camping trips. Get lifejackets. Wrap up warm, take spare clothing. Wee feet get cold, which means it’s time to get out and have run about.
We recently bought a 2nd hand reinforced PVC thing off Gumtree to take on holiday in the summer to avoid lugging 16′ Open boats about.