Hi,
A few tips:
+ concerning your lack of confidence in your tech/design skills
On tech: if you don't know how to install/run/use/add plugins wordpress do this first or don't get into SEO. It will get lightly technical but not as much as you think so. I don't think I've ever edited wordpress code at all. So, learn wordpress first
On design: ugly sells well: install wordpress, download from here a basic theme for SEO : schema, add some plugins like Tablepress and WP review and you're good to go.
> Buying a premade website is bad. You need to learn things yourself to get better at it.
+ building authority to your site
Lol to the guy that told you that he does not linking to his pages... You will need to build links:
How to?
Build a social fortress: simple. Youtube / google + FB, twitter ... 6 /7 of them. Syndicate content on your blog with jetpack (wordpress plugin)
Learn to build a PBN: find auction domains, buy them gradually. This is expensive but gives you a massive headstart and control on your links.
Web 2.0 are all very nice (btw they are public blogging plaforms like blogger, blogspot, tumblr and also social networks...)
Contribute on dedicated forums: this is to building links but also traffic.
A few comments here and there.
+ building one or many websites:
an amazon niche site can rank with 20k words. So you can/should create more websites and no burn your ressources on one. Especially if you build a PBN you can then use this to rank other sites.
Then, build your passion project as well, something you like and make it a big site.
+ niche
Seriously the hard part. I've spend so much time on Amazon. There's a lot of competition on big products that sell well and expensive and it makes it difficult to rank. So, well spend some time there and go for a product that maybe cheaper like > $60 at least with reviews
+ keyword research
Now people say it's hard but it's really not that bad:
Take competitors websites (ranking on first page) and run them in ahref/semrush (you should buy a subscription to a group buy for this: search it on FB there are some (group the Lab and Lionzeal marketplace).
You have a list of keyword they are ranking for. Well this is your target. You can tarket the big boys, or low hanging fruits with 500+ searches with buyer intent (product name...) and rank on that.
+ blogs to follow
I don't follow many blogs but I've read and learnt a lot on : backlinko, matt diggity, lionzeal (podcasts, too bad I hate the aggrssive promotion by Daryl sometimes...), cloud living sometimes.
About me:
I don't make millions online. I started my first amazon niche site 2 years ago and I now make about $1500-2000/m. But I don't work on my websites... I have a regular job and a family to take care of.
When I say I dont work on my website, I mean, when I create a website now it takes me a good 10 hours. Then, some care at the beginning but when it's ranking I tend to go lazy and do other things.
Good luck
OMG that was long!