Hey!
I'm 17 but I hope I can help.
I'm doing work experience for psychology atm too, I'm doing it with the NHS, St Johns and Childline.
Childline starts you off into getting knowledge into children, St Johns proves you can work with people and under pressure and the NHS, well, it's good experience!
You can get in contact with St Johns via the website same applies to childline.
And mail the local NHS pct in your area, it's what I did!
Also, if/when your 18, volunteer with samaritans, it gives knowledge into adults. Then you'll have a range of working with children, adults and under pressure.
Also, as other people have been saying look around, try vinspired and stuff like that.
I'm sure you'll gain a lot of experience by doing these!
Paige x