If doing it on a startup type budget:
Quick, inexpensive, mobile friendly website builder with blog: strikingly.com or wix.com
Both usually integrate with any other service (appt. scheduling/storefront) at least via html, and many they are already set to work with with just a click of a button.
Good storefronts: etsy.com for handmade or vintage products, shopify.com or squarespace.com for just product (not handmade or vintage)
you already use spafinder for booking, so it should just get tied into your website.
Mailchimp.com for a starter email list. Growing your email list should be priority #1 for your website, then, just focus sales and relationship development on the people on your list.
buffer.com and/or hootsuite.com to schedule social media posts across most platforms. bonus: www.quuu.co will pull related content for you and connect to buffer to auto post to your sm platforms.
sumo.com for the tools that will help you get people signed up on your website and instantly added to your mailchimp list. specifically – welcome mat, listbuilder, and smartbar. also heatmaps and content analysis will help you see how people interact with your website to make it better and better for them.
This is a quick and dirty guide and to use all these tools to set up a full online platform for yourself will still take probably at least 60 hours total for a newbie – from setting everything up to inputing all your copy and products, etc, but most of these tools can be used at the starter level for free so at least you don’t invest thousands in a website that doesn’t do what you need. All these tools can be upgraded in the future to meet your increasing demands.
Note: if you end up hiring me to do some of this work for you and/or maintenance I may use different tools, for example, I would build a wordpress site for you instead, and that process may prepare you better for future growth, but will be more expensive and can also be done in the future when your incoming business demands it.
All the tools I mentioned will be able to easily upgrade/roll into a wordpress site in the future.