Light : Bright light will keep those leaves fanned out.
Water: Keep the soil lightly moist, don’t let him sit in soggy soil and let the soil dry out a wee bit in between waterings but never completely.
Humidity: These guys are from tropical roots so will enjoy higher humidity. You can mist regularly, sit him with some other plants or pop him in a bathroom/kitchen.
Temperature: Normal household temperature will be fine for your mimosa, just don’t let him get too cold.
Food: You can feed your mimosa ¼ strength fertiliser every two weeks in spring/summer.
Toxicity: Mimosa Pudica are a great addition to your menagerie of beasts (human an otherwise)