Hey.
A reference will be from one of your teachers, not from someone outside of academics. However, in terms of work experience, I think it's worth a shot getting in touch with your local msp.
I'm also in S5 just now, and last summer I decided to email to local museum to ask if I could volunteer for the summer. They ended up saying yes, and it was an amazing experience.
In my email, I introduced myself (name, age, where I'm from, what school I attend, year, the qualifications I was studying and my predicted grades, and why I was interested in volunteering). I then attached a pdf of my CV (I used My World of Work to make it), and linked my LinkedIn account.
At that time, I also emailed a local newspaper for work experience. Whilst this didn't go ahead due to scheduling conflicts, they were more than willing to take me on for a week.
The worst thing your msp can do is say no, but in my experience, people are more likely to say yes than you might think. You never know unless you go for it.
Lastly, I recommend emailing at least a couple of months ahead. E.g., if you want to do it in July, then email in April/early May.
I hope this helps, and if you have any more questions, feel free to ask me. 😊