A:AnswerYes you do need Wi-Fi to be able to access the apps and games and websites on the tablet. Once connected, you can download the same content for use when not connected to WiFi
A:AnswerYes, you need to but a screen protector.
Any one that has a good review from Amazon or Best Buy (keyword: Amazon Fire 7 screen protector):
https://www.amazon.com/s?k=Fire+7+screen+protector&i=electronics&ref=nb_sb_noss_2