first time foster!

we got our foster kitten, megatron, today! she’s 5-6 weeks and really fun. i have an 8 year old cat that i adopted as an adult (they’re quarantined don’t worry!!) so i don’t have too much experience with kittens. i don’t want to overwhelm her the first day, but people also recommended frequent play time and socialization. how long should i be leaving her alone today to give her time to adjust? how frequently should i be checking in on her and playing with her?

the shelter also recommended leaving her mush out all day so she can eat whenever. is this accurate? i thought that kittens sort of needed a schedule and routine? any recommendations, tips, tricks are more than appreciated!