If your cat has no obvious symptoms or weakness, you don't need to go. I once took a stray cat to check. In the absence of symptoms, the veterinarian just took the cat's temperature, checked the male and female, looked at her teeth for how old she was, looked at her ears for ear mites, looked at her eyes for malnutrition and anemia (anemia is also caused by malnutrition), listened to her heartbeat, and then pulled the cat to see if she was weak. Then, if your cat looks weak, he will let you observe it for one night and come back tomorrow, mainly to see if it has eaten, vomited, diarrhea and inflammation. No, I gave him 5 yuan for medical treatment and went home. See if you want to see a doctor according to your cat's condition. I don't think it makes much sense, because the kitten who went to see the doctor died of exhaustion the next day. There is no difference between seeing and not seeing.
If I were you, I would mainly check whether there is any trauma or tinea at home (alopecia areata can basically be diagnosed with tinea), and neither case needs an injection. Take good care of it and don't abandon it.