First and foremost, you're in for a long haul. Not with this article--with traditional publishing. Let me paint you a picture of the BEST case scenario.
You write a book that happens to be well written, easily pitchable, and perfect for the current market. Then you write the perfect query package (harder to do than you likely think) and submit to your dream agents. They all want you, you take a couple weeks making your pick, then you sign a contract. After that you go through revisions with your agent. For argument's sake, let's say your book was perfect and needed zero revision (news flash, this doesn't ever happen) and your agent already had a list of perfect editors who all want it and you go on submission. A bidding war ensues immediately, you pick one and sign a contract with them. Hooray! Bells and whistles! But guess what? Even if ALL those things went perfectly, your book still won't be coming out for maybe a year and a half to two years. I don't have personal experience with this yet, but I see the dates people are announcing on Twitter/X.
Now for a more realistic scenario--mine. I wrote my first book in 2019, then shelved it immediately after I got pregnant again and had debilitating morning sickness. I didn't get back to it again until the beginning of 2023. Since then I've written and queried four other books (including the one I'm querying right now). I've had the sporadic full request, but nothing has panned out yet. I currently have one full and one partial out (and quite a few I haven't heard back on yet). For the full request, I was told to give her 6 months to review it, and to nudge her if I haven't heard back by then.
Six months, and that's not even unusual. And If that situation played out and I signed with that agent, we would then need to do revisions before going "on sub" with the project, which could potentially take another 6-12 months (or longer? I've never gotten this far, obviously, but I know people who've waited for a very long time.) A lot of people have to shelve the project and pursue something else. Some people even have to start the query process all over again for a variety of reasons (agent quite or dies, no longer want to rep your genre, you want to switch your genre, etc). And assuming it did work out, then there'd be a nice long wait until the book actually came out.
Basically, publishing can be a slog. So if you want to pursue this route, you'll need to be patient. If you have a loved one going through this, know that the long timeline isn't indicative of their skill set.