I often serve grilled steak and shrimp for summer meals with guests. For sides, I usually do:
Oven roasted potatoes: I use the mini potatoes, halved and tossed with EVOO and salt and pepper. Cook cut side down.
Green salad: Bibb lettuce with avocado, green pepper, cucumber and pepitas with a lime vinaigrette.
Grilled corn and poblano salad:
https://www.allrecipes.com/recipe/222849/grilled-corn-and-poblano-salad-with-chipotle-vinaigrette/
I serve home made salsa and guacamole on the side. For dessert I do brownies with vanilla ice cream and an assortment of berries.
Almost everything can be prepped in advance so only the grilling and potatoes needs to be done after guests arrive.