A slow website is more than a minor inconvenience. Visitors trying a few sites won't wait for a slow page to load, so you're missing out on potential clients. Even those who persist might eventualyl get frustrated if the slow experience continues through to a booking form.
Also, they might not find you in the first place! Google penalises slow sites in its rankings.
So your slow site may be costing you money.
Choose fast hosting
Cheaper options are often slower options too. Compare your choices and find a good balance between cost and speed.
For Static Websites
For online stores and other "dynamic" sites with carts and stuff that adapt for each user, skip this. This is for "brochure" style stites that show everyone the same set of pages: "static" pages.
Consider whether using WordPress is the right option – there might be an option to build a static site in a way that doesn't need to run software each time it delivers a page. For example, I often use RapidWeaver for these sites. There is a trade-off here especially if you know and love WordPress.
If you do choose WordPress, it has plugins that can "cache" your page content, speeding up delivery of pages that haven't changed. For example, W3 Total Cache, WP Super Cache and Cache Enabler may be good options.\
For Dynamic Websites
For dynamic content like online stores, you need raw speed from your hosting. It might cost more but it'll matter. This means give PHP lots of memory and don't choose hosting with too many sites per physical computer.
Don't Collect All The Plugins
Minimise how many WordPress Plugins you use. Each plugin has a speed cost, so don't just "collect them all" - keep only the ones that make a real difference.
There is a balance to find between image quality and image file size. A smaller file size will load faster but can look more "grainy" if you go too far.
You might see hype about "Next Gen" image formats like WebP and HEIF. As of early 2020 it is still too soon to worry about those. At the moment there isn't one you can use across all browsers, because the browser makers are still arguing about which is best. Stick to good quality current versions of JPEG until they sort it out.
An option like CloudFlare can speed up your site and add a layer of security at the same time, if you're not sure you've covered the basics of security yourself.