Obviously things might change and entey requirements might be different in a couple of years when u graduate but you don't need to take alevels you would need to sit the GMASAT as most universities would consider psychology a non life science degree (there might be some exceptions ) and some universities outright don't accept someone unless they have a life science undergraduate but places like st goerges,Chester, scotgem, Nottingham (I'm sure there's a few more) you need gamsat and minimum 2.1 degree. I would dip your toes in and do the gamsat in your second year so next September if finances and time permits, so you can see what your working with. If I'm not wrong u can apply during your final year or at the start of your final year. The gamsat is valid for 2 years so you can attempt it September 2025 and March 2026 and September 2026 to apply Oct 2026 for entey Sept 2027. Let me know if you want to know more