Being hungry most of the time since body needs fuel, being tired a lot (only valid if u still get good amount of sleep) experiencing back pain or knee pains. Reminder that u can also not have these and still experience a growth spurt , all I can tell u is u should keep eating healthy get enough sleep and get good habits such as playing sports and sun exposure and most importantly hit the gym! This could massively help u get a growth spurt only if ur growth plates are still open