What are the best plugins or options so my site Wordpress does not spend as much cpu?

My site has been offline for 24 hours because it exceeded the cpu limit. Here I would like to know, what would be the best plugins or options, that you know, to avoid mistakes like these.
I currently installed Swift, I adjusted correctly, I activated the cache, it even limited the threads to 3. But anyway my site spent cpu and offline now.
Do you know another plugin that can help solve this problem?
Remember also that my site is simple and light, and does not receive a huge number of visits.
I want to fix it as soon as possible, so I do not have any more problems of this kind.
I'm grateful

I just created a site lately. Here's a few things I've done. I wanted to list exact plugins but cant even open script installation at this time. 1. use an image compressor 2. use a good lightbox on images, with small thumbnail initially on page. 3. use a good cleaner to clean up revisions... 4. use a lazy load to load resources. Large graphics is the killer.

My site will open immediately, IF all the servers are functioning. At present their servers are only up half the time. I see some serious issues here, they may be periodic. I only hope that's the case.


I finally got in. See if these plugins help: Responsive Lightbox & Gallery, a3 Lazy Load, Webcraftic Robin image optimizer, WP-Sweep. I cut the height of Twenty Seventeen Front Page image down to about 320 pixels.