problrm ” eror 404″

hello,
this is my blog’s problem. my blog’s url is https://www.britney-spears-diet.info
when I try to reach the following webpages:
“24 Hour Fitness – Your Way to A Healthier Body”
“Celebrities Weight Loss: What’s Their Secret?”
“Fitness Woman – Ways for a Healthier You”
i cannot see these pages. I can see written “eror 404” or “the page cannot be found” somethig like that.
i need this thing to be repaired as soon as poosible that my website will be useful. so please give me an answer what should I do.
If this is not the right blog for this question, please write me which one is.
thank alot
amitai