I need 1 appointment

Good. Ask Apple for one, not Google.

You got it. 1 appointment booked for you. Don't be late. JK. Go to Apple Support online and go thru repair click-questions. Or call Apple Support. Either way, if they can't guide you thru a self fix, they will help u make an appt. Or, you can just go there anytime you want as it's 24hr store. Peak times about 1 hour wait, slow times like 11pm - 8am there's hardly a wait.

How to take an appointment?

I need to change battery in my old Phone 6. Preferable time is 5-6 PM on Tuesday 07.10.2018

I NEED an appointment..