1) Get a summer job
Not only will this get you out of the house but you'll be earning money too! A summer job is great for building up your CV and you may even make friends whilst doing it. Good places to look include ice-cream shops, local holiday parks or leisure centres, bars, cafes and restaurants, and retailers such as Primark, Argos or your local supermarket.
2) Volunteer
Similarly, this one will also help boost your CV! This looks great to future employers and there are a multitude of places to volunteer at according to your interests! I'm planning to volunteer at my local museum but you could volunteer at a hospital, animal centre, youth club, library etc!
3) Start a blog
Starting a blog is great as it gives you a creative outlet and a place to share your thoughts. It will also help you develop your writing skills whilst documenting aspects of your life that you want to share.
4) Start a Youtube channel
This is similar to the blog one. If you struggle with writing or just prefer to talk or share visual creations then this is another great idea and can help improve your communication skills whilst making friends. I have a Youtube channel and because of it I have gained confidence and made some great friends.
5) Educate yourself
Whether this be through taking a course, visiting a museum/gallery, watching documentaries or reading a book, educating yourself is so important. You are never going to have a summer as long as you do as a teenager/young adult, so make the most of it and use this time to expand your knowledge on a subject you find interesting!