Here's some good websites and resources for graduates entering the industry.
As a starting point you'll need to do your research and think about what type of agency/ company you'd like to work for and check their websites and social media for job openings, then apply with your CV, portfolio and a few sentences about you.
Good additional resources are:
https://youngcreativecouncil.com/ for general advice and book crits Young Creative Council
I LIKE NETWORKING https://ilikenetworking.uk/ shares jobs and advice on a regular basis
https://www.thearena.org.uk/ The Arena offer tons of advice and articles for creative grads.
I've been asked to host a panel for D&AD New Blood Festival on the 7th July about getting into the industry too, check that out!
I also have content for graduates too on my insta, with one IGTV focused on interview tips for graduates and juniors https://www.instagram.com/nikkylylecreative/channel/