Toddler is sick

I can't seem to get an appointment with my son's (3 year old) pediatrician or anyone in the office or in another location. He has a barking, dry cough and a runny nose. Another thing is he just developed a fever . It isn't a high grade but I was thinking maybe going to urgent care tomorrow. Or what advice does anyone have ? He doesn't usually get sick so I want to know what to watch out for and whats considered an emergency or what's considered a take care at home. I will also call the advice nurse but somtime they don't help much. And I get it isn't their job. I just want tips and advice from a parent as well. Thank you.