Wellllll...I don't know much about wedding photography but I do know a little about websites and the second part of your post isn't necessarily true.
Hosting fees aside, there's no reason why a "free" website (I assume we're talking about templates here) can't be every bit as good, or even better, than commercial templates.
Commercial templates are only valuable because people can't be bothered doing their own coding. If you learn a bit of coding, then you can just install a basic, free wordpress (or whatever) template and go nuts customising it. Then you have a site that's absolutely tailored to your own needs.
It's really not that hard either. Most of the fearsome stuff is already taken care of within whatever CMS you're using (wordpress or something). And it is hugely rewarding. Start with small modifications to the basic template and add more as you become more knowledgable and skilled. The University of Google is your gateway to thousands of excellent, free, resources that will show you how to do it.
And if anyone tells you that you need to pay them, directly or indirectly, to get your site higher in rankings then they are, frankly, blowing smoke up your backside. There's nothing necessarily special about "professional sites" that makes them rank higher.
There's nothing wrong with professional sites. They serve a function for people who can't be bothered, are scared of, or don't have time to learn coding. But saying you'll never get anywhere with a free site is nonsense.
Well!!! (is that how it's done?)
I don't know much about writing websites*....
That's quite important as you'll see.
As a newly professional photographer you'll be learning:
How to be a better photographer.
How to sell.
All about accounting and the tax system and NI
How to get up and manage a website
What other ways are there to promote yourself, networking, advertising, flyers? mailshots, buying customer lists.
How do you get involved in wedding fayres, are they right for you
A really efficient processing and backup regime
How to deal with prospective customers
And you're suggesting that we add 'learning a bit of HTML and CSS to compete with professional web designers'

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For someone that's never had a website before, just understanding how hosting and domain names work, what's a content management system and how will it help them, how do they get a good google ranking, how to write successful copy, what images are suitable for web use, how do they ensure they have the necessary permission from their customers to use images - is plenty to learn

. Are you really suggesting from the OPs postings so far that learning how to code a site is a priority :shrug:.
And btw it might have helped if you'd read the thread; free websites meant Weebly

Really - not paid hosting and a good free template - Weebly
*I've worked in IT for over 15 years, I can code in VBA, manage servers and backups, user admin, and I'm an 'expert' in many applications, and learning HTML is a bit of a stretch for me :shrug: People who can code always assume that 'anyone can learn' without thinking through whether learning is actually worth it. Because if we look at the numbers, the profit from a cheap wedding is enough money to get a really good website up**, it's really a no brainer as a business decision

.
**That makes it cheaper than
A pro grade lens
A sample album pack
A decent camera bag
A tripod
An OEM flashgun
A years running of your phone
Servicing your car
Your business insurance
When you're running a business, paying for other peoples expertise is often miles cheaper than doing it yourself.