Feel like I ended up at a bad university, what can I do?

Exactly as the title reads.

I'll be the first to admit I didn't try very hard during my education and coasted through the majority of it, including my A-levels where I ended up getting BCC, in business, law and politics. Afterwards, I managed to get accepted into Royal Holloway (through clearing) on a Criminology and Sociology course however I quickly realised I wanted to switch to computer science, which I did in my GCSE's and applied to Kingston university the following year.

Now don't get me wrong, the university isn't that bad and I'm grateful I've made it this far at all but throughout the past year I feel like reality has hit me like a truck and I really regret being so passive during high school and sixth form. I feel like I'm capable of so much more and if I'd have just bothered to put some effort in I could have made it into a far better university. I'm anxious that I've missed out on crucial opportunities to make a better future for myself and I now want to make up for it.

And so my question is, what can I do to improve my future prospects?

My plan at the moment is to complete my degree at Kingston and then go on to do a masters at a higher ranking university. Is it realistic to aim for a Russel group university in my position??

As well as this, I will also have to opportunity to go into a work placement in my third year to gain experience.

I'm also independently studying A-level maths using courses on websites like edx on the side as while most other computer science courses have a lot of maths involved, Kingston has very little (to be expected). Do these online courses realistically count for anything towards applying for a masters?

If anyone was/is in a similar position or has any advice at all please let me know.

What class of degree are you likely to get?

If I do as well as I did in my first year, then a 1st.

If I do as well as I did in my first year, then a 1st.

Then you should be able to get into a "better" uni for a master's.

A year in industry would be a good move. [PS It's Russell btw and they aren't the best for getting a job in the industry]