I have a psychology degree, it's a very good degree from one of the top unis in the country for the subject.
The degree is very statistical with a lot of maths. You'll follow the same stats courses as statistics students until 2nd year. It's all about setting up and running research, and analysing the resulting data. You'll then do other modules that give you a flavour of each different branch of psychology.
Should you wish to use the degree in your work, you then need to do a post graduate degree in your chosen specialism.
The popular specialisms (clinical psychology being the most popular) are practically impossible to get into. The postgrad course is part work based, part uni based and is NHS funded. Think 400 applicants for 4 jobs per year here. If you don't get in you need to wait till next year and reapply again with another 399 applicants.
If you were interested in another area eg counselling, educational etc then the odds are a bit better.
In order to get on to ANY postgrad course you need experience of working as a research assistant which is low paid. There is zero hope of getting onto a postgrad without this work experience, as applicants are ten a penny.
Having said that, I enjoyed my degree and I love the knowledge that it gave me. It doesn't help me in my job at all beyond ticking the box if having any degree. I do wish I'd known this before embarking on a 4 year degree as I would have picked a more vocational subject.