Resin can warp ever so slightly under strong direct sunlight or extreme heat. If this happens, take the piece away from the source and it will go back to its original shape.
Epoxy resin is a hard-wearing and durable substance, so all you need is a soft clean and mild soap to clean. It is not suitable for dishwashers and using harsh cleaning chemicals is not recommended.
Resin isn't scratch resistant so to keep your piece looking great keep it away from sharp objects.