There are many different ways to do things. It all depends on what works for you. Some people swear by spam. Some people rank spun content. Some people only want to post content that is at least 10$/100 words.
Eventually, SEO is not that hard. It’s keyword research + content + links. Everything else is secondary.
The more competitive they keywords, the more you need to optimize the content and links. For low comp keywords, you don’t need to know any SEO.
If you want my advice, find 100 low competition keywords in your niche before you write a single word or even buy a domain. Once that’s done, write all 100 articles before moving on to another project. No need to bother with links. Rinse and repeat.
I don’t remember exactly how long it took to get indexed but I’m sure it wasn’t more than a few days. Newly registered domains seem to get crawled pretty quickly.