Hello @Rosieblue12
Like I mentioned, I used to work as a domiciliary worker. (I should mention that it was not in the U.K., though, but perhaps I can share some useful advice anyway)
First of all, both @MamaBearThius and @Snowpatrolling have good advice.
Here is some advice from me!
The day can be hectic and intense, but you are new to the job! It will feel better soon. Most important, you will soon know the persons you care for better, which will make everything easier. You will know their routines and their habits. Soon you will also know your way better around the clients houses, and you will be able to be more efficient.
I always used to think "One client at the time, one task at the time" when I sometimes got overwhelmed. When you have a list of 10 people you shall visit during a day, it's no help to think about client nr 8 when you are at client nr 3's place. Of course you have to plan your day, and plan ahead, but you have to focus on the person you are helping at the moment. Be present for that person.
Like @MamaBearThius wrote, the persons you care for are most likely used to that the domiciliary worker does not arrive on exactly the same time every day - things happen, there might be traffic, etc. If you think you are going to be very late, stop the car and call, so they know where you and that you are on your way.
Or ask someone on your team if they can help you out.
Enjoy your time in the car! That was one of my favourite parts of the job, driving around in different neighbourhoods, looking at interesting houses and beautiful nature (I worked in the countryside, so I sometimes had to drive quite a distance between the clients.)
Good luck!