Yes Cloudflare can help to speed up your WordPress site because your users can download a version of your site from a geographically closer server to their particular computer (or mobile device) in which they are loading your site on.
How does Cloudflare speed up your site?
Cloudflare is a CDN or Content Delivery Network. This means that by signing your website up to Cloudflare they will distribute a copy of your site files to many many servers in their network of servers around the world.
This is beneficial to your user because when they are loading your site they will be loading it from a server which is geographically closer to them. This means there will be less lag time in loading it as the digital information needs only to travel a smaller distance than if the server with your site files on it was in a location farther away from your user.
How to set up Cloudflare on your WordPress site?
Setting up a Cloudflare Account for your WordPress site is about a 30 minute process and is free for the basic plan.