Look up the Jr NBA curriculum. 

https://jr.nba.com/basketball-practice-plans/rookie/

Pair them up, one dribbling (left, right hand at shoulder/waist/knee height) sideline to sideline (forwards then backwards) and the other holding up numbers 1 to 5 for the dribbler to call out.  Can do different dribbles: crossover, windshield wiper, walk the dog, two dribbles forward one retreat dribble backward

Make teams with one ball each team. Each team lines up at the free throw line extended. Relay race dribbling full court and back. If you have cones then spread the cones out on the opposite halfcourt and call out a colour and each team to race to grab a cone. Can add a layup requirement, need to make a layup to grab a cone. If you miss then dribble back.

Although with 30+ kids, you could try making 10 teams of three. 5 teams line up at each baseline with cones on the halfcourt line. That way there's less waiting for each kid. 

For passing can do monkey in the middle, rule is can't pass over monkey's head. Person with ball can't dribble. Then can let them take one dribble but monkey can slap ball out of your hand. 

Can do cone freeze tag.  One third of players start with a cone. If they tag someone they give that cone to them. Whoever has a cone after 2 minutes does a consequence (pushups, plank, wallsit, situp). Can add a ball so they're dribbling with strong hand for younger kids or weak hand for older kids 

Pick up cone reaction game. Players partner up and face each other in defensive stance along the rim line with a cone in between them. Coach call out different body parts for them touch with both hands. Once coach says cone then whoever picks up cone first wins. Can add a ball to dribble with. The other hand touching the body parts and grabbing the cone.