Original post by GreuGetting and internship - Network. Use LinkedIn, go to lectures organised by professional societies, talk to people at those lectures, get involvee with the local graduates and students committee of your course's accrediting body (BCS, ICE, IMechE, IET, whatever).
If you are studying at a top 20 university, applying for internships online might work, but if not, making yourself known gives you much higher chances. This comes from personal experience.
Getting a first class degree - More studying, and more time dedicated to relaxing, less time drinking and partying. If you are a very smart person who physiologically can have energy on not so much sleep, can handle lots of alcohol or are able to memorise a lot of stuff in a short period of time before exams and take advantage of group work with hard working people, then by all means, do whatever you want. (I will probably get some hate for this)
Having a first doesn't mean you are smart though. It means you know how and when to study. Ask me questions from the modules that I didn't enjoy during my bachelor's and I don't know how to answer them, even if I finished with a first. Again, this comes from personal experience.