I've helped a salon create really nice growth through my digital marketing efforts (and I too was a novice). I wouldn't suggest doing course, I consider it a bit of a waste of money because there's really no secrets, most information is readily available on Reddit and Google.
Here's some steps that were critical for me:
* 1: Create a modern, attractive, and mobile-optimised website. Be sure to have a irresistible CTA (We have 25% first visit vouchers, they simply put their email and automatically get voucher sent to their email). Have all relevant information easily noticeable (contact details, location, prices, work examples). Be sure to keep it personal, act friendly, tell them about yourself, these people are trusting you with their hair, you have to make them believe you're the best option. Ultimately, this is the key to SEO (will explain later)
2: Get your Google Listing (important), Facebook and Instagram up to date (all contact information, website link, reviews, high quality photos etc). For us, reviews are the key, full stop (well, reviews are key for most service based businesses). You need to focus on getting happy clients to rate you well.
3: Advertising wise - Google AdWords has had the biggest positive impact for us. It has been a great investment, with great results. Just make sure you understand the metrics so you can focus on improving your customer funnel (e.g. CTR, conversions). We've tried Facebook, but hasn't shown the greatest ROI, but we do use FB advertising during events like Christmas, etc.
For a local business, SEO (getting on top of search engine results) plays a huge part, but requires effort. It took 4-5 months, but I was able to rank our website on top for a bunch of keywords in our town. Just from that, we get a lot of organic traffic and conversions. Actions you can take: listing your business in business directories, positive reviews, informative blog posts on your website, optimising your website, getting your website linked on high authority websites.
I could really go on forever. I've learnt a lot over the past 2 years with trial and error, but it has all resulted in positive revenue growth for the beauty salon. If you have any questions, just let me know. Happy to help out! :)