Google made it official that page speed has a direct effect on ranking so here are 4 tips to speed up your WordPress site. Start off by using a good compression tool to optimize all your images – I like to use https://compressor.io/compress. If you have lots of images on your site already https://wordpress.org/plugins/wp-smushit/ is quite a good option. Once done install the 3 plugins listed below to supercharge your site.
Google Mobile Rank
Google Desktop RankSpeed up WordPress Plugins
These are 3 plugins that really work well together to speed up your site.
1. https://wordpress.org/plugins/fast-velocity-minify/ Works out of the box.
2. https://wordpress.org/plugins/wp-super-cache/ There are plenty of guides online how to configure it.
3. https://wordpress.org/plugins/a3-lazy-load/ Works out of the box.