CPU Usage is common when using wordpress, also there is no need to directly tag Admin, He will come when he comes, but the reason this is a forum and not a support ticket system is so everyone can help you
Also, This can be due to too many visitors at one time, as many people loading many php scripts (of which are very heavy in wordpress) can overload the system. (As Katufo says) so unless you have accidentally left something on, the only solution is to minimize your visitors
Because of its big code, WordPress is designed for medium site & above.
Thatās why I donāt use WordPress in this free hosting for my site. For blogging, I simply use Blogger.
& other reason, itās always be targeted by hacker.
This is my site log (eventhough I donāt use WordPress):