This is two relationship questions been help?

My guy friend likes me and I can tell he's flirting he used to text me like every night. He acts the same way at school everyday but now since my friends have been saying awe cute couple, and lately we barley text but the day lifes the same... First question, Is he scared about something? And Second question is how can I tell him I like him, and when and where should i if/not tell him? Hope u understand the questions thanks!! I'll answer ur question too!!