it's boring for me as well but i try to make the most of it. it mostly depends on where you live. call your friends ask them to go out , take pictures or just talk and make plans for the future , maybe play some games as well. if you can't go on a beach, find other place to swim and sunbathe , pools or etc. you could develop a talent you have for example painting or crafting or something. do DIYs and exercise , you could also buy a book and read outside in a park for example. you could also start a blog and write, maybe you have excellent writing skills. don't forget the tv shows! i know laying on a bed eating food and watching something is not the best idea of summer but if you find the tv show that's very interesting for you, you will have fun watching it. i myself love vampire diaries , jane the virgin , teen wolf and all cw shows. just get creative and i'm sure you'll find something to do.

Read a book, listen to music, go out walking, listen to a lecture on ted.com, write an article on italki, answer someone else's question on italki, watch a movie on your computer... many things.

First of all your sentence "Is is a so boring summer holiday" doesn't sound right. Instead you can say "The summer holidays have been boring so far" Also I recommend maybe joining a local club. Maybe try fishing, read a book or learn a language?