Hi and Welcome,
One tip I will give (and I'm sure others will agree/disagree as they see fit) is not to price up jobs by the hour.
You will soon find that a job you think will take 4 hours, can be completed in 3.
This will benefit you if you price for the job, not the time. By pricing the job in your head as taking 4 hours on your initial rate (£8 x 4) and quoting your customer £32, you could soon find yourself getting your £32 for 3 hours.
Just something I've started doing recently, as I didn't want neighbours, etc. telling my customers that I was only there for 2.5 instead of 3 hours.
Now, they get a price and like it or lump it! How long it takes is irrelevant.