What s wrong with my macbook air Internet doesn't work?

every time I use the internet something happens pages like facebook, wikipedia, and youtube (sites I usually use) work just fine, but whenever I use a website i don t usually use, every other website stops working except for the ones I usually use. The only way to fix this is by turning my macbook on and off again, but doing this 30 times a day gets really annoying since I can only use one different website everytime I turn on my macbook has this ever happened to you, what did you do to fix it