Do you call the doctor

Hey guys as a ftm I remember always calling my doctor as soon as baby was sick had any fever.

Now he's four has a fever, cough, threw up in the morning, his stomach hurts today doesn't want to leave the bed and is groaning my stomach hurts. Got sick from preschool has coughed all night despite cough syrup and children Tylenol

Idk if I should do fever reducer, and give fluids and see if its a cold or stomach flu but idk what you do for older children do you pick up the phone call Dr when they have a fever?

What do you guys do

Now fever is 102 and won't eat anything not even ice cream does drink water I'm thinking of going to ER? Or going to see his doctor