Look at the course structure - not just the general description of the course.
What units are available in each year, what is compulsory, what/how many units can you choose, do these interest you, etc etc.
If you can't find this easily on the Uni website (tip - search 'unit catalogue', or 'course catalogue'), then email the Uni and ask for the link. It shouldnt be 'secret' - you are spending ££ on a degree, you need to know that you will enjoy it and its what you want.
Are there any extras like 'placements', opportunities for study abroad, units in other subjects etc etc These sort of things help you develop confidence and maturity, add to your CV and make you more 'interesting' to employers.
If you can't visit the Unis in person, then look at the Open Day films and 'student videos' on YouTube. These will give you a good idea about what the Uni looks like and what students think about their course. Can you see yourself there - often gut reaction is the decider.
Finally, make sure the course is accredited by BPS if you think you might eventually work in this area. Without it, you work options are more limited. Check here :
https://www.bps.org.uk/public/become-psychologist