Cocker Spaniel. Not too big (poo scales on a per kilo basis 😯 ), great with kids, good on the trails, separation anxiety (so won’t chase rabbits miles over fields), don’t seem to lose too much hair, only smell when wet. Good life expectancy (10-12 years), and not so big that a second would be too many in old age. Get one like ours and it will run away from water (an unusual trait in spaniels). Ours likes exercise, but to be honest, he prefers company…
Springers have a LOT of energy and are a bit mad. Labradors seem to shed hair like I’ve never seen. And smell. I don’t really do big poos, hair and smells.
As a rule, rescue centres won’t let you have a dog as a first time owner if you have children.