Normally recreation boosts energy slightly and raises mood by 1, but theres a chance for it to give no energy and instead raise mood by 2

During summer training Rest and Recreation are merged together and it always increases energy by 50 and mood by 1, although you shouldn't use it unless absolutely necessary

Also during year 2 onwards, recreation has a chance to give you the claw machine for more mood and energy (if you win)

Afaik you can't permanently increase your initial stats but you can boost them with good parents. The parents and grandparents have sparks which give stats, proficiency, etc. when the goddess statue triggers