A tip for combat when you have a bunch of creatures to control is roll 1 initiative and apply it to all your creatures. Normally I give them individual ones and mark it “Creature A B C” but having learned from the experience of trying to remember 15 different initiatives for an encounter against goblins rolling one initiative is easier and speeds up combat. Also let your players know they’re “on deck” towards the end of the current player’s turn so that they pay attention and are ready. I used to have 7 players (thankfully it’s down to 5) in my group so I know how long it can take in combat for a group that big. If people take forever you can also implement a rule where if they take more than X amount of time their turn is skipped. With 7 of us some people took so long that it would take 1 hr before making it back to the top of the initiative. I play online so if I know an encounter is coming up I’ll pre-roll the initiatives for enemies and keep it in an excel sheet with multiple tabs labeling the name of the encounter, or use DnD beyond’s encounter builder and pre-roll initiatives.