The main issue i saw people have each year was finding things to say in their personal statement. A lot only focused on academics and then had nothing to write about in the statement.
Try and get a part time job, join some extracurricular, something related to maths, engineering would be good but not everything, do something fun too to show you have hobbies. Take on volunteering etc
I personally did volunteering at my local Girlguides for 6 months. It was only 3 hours a week and I didnt really enjoy it but it made my statement stand out by showing i cared for my community. I had a part time retail job which showed I had commitment and good time management skills to do that alongside full tkme education, i got involved in my 6th forms eco club and helped create an eco friendly school environment, took part in a challenge that ended with my school going to London for it. I created an LGBT friendly club at my school and promoted it in front of assemblies to create an inclusive environment for everyone.
To be degree specific i did 2 virtual springpod work experiences in accounting and finance to show i wanted to learn more about the area i was applying to. (Defo check out springpod). I also did the EPQ based around my subject area and spoke on that as well as mention wider reading such as using the free resources available on the open University.
I spoke about being from a disadvantaged working background and how that shaped me as a person growing up and created this hard working ethic that led me to pursue and do so many different things.