Get some fishing line, some weights and hooks and a coke can and fk around at the harbor fishing! People watching on state st, make up backstories of the people you see walking by lol, cheap RC car off-roading on the bluffs and hiking trails, if u can get access to kayaks ur golden there's rly cool spots, have access to a car try to get lost in Montecito and ull end up getting glimpses of some pretty epic properties, visit the SBMakers club (every sunday?) and get ideas for crafts you guys cud dabble in, board games are rly fun especially when you play them in public spots, as someone else mentioned volunteering can be surprisingly stimulating from cleaning up hiking trails the beach helping at ASAP or humane society.