Hi Joe, I have had some experience creating articles on Wikipedia (around 60 - full list here), and contributed to many more, and have learned a little each time. Here is an attempt to distill most of what I have learned.

First, get yourself a Wikipedia User Account - you can create or edit without one but will not be taken very seriously.

Next, you have to address in your own mind the wikipedia "notability" requirement for the topic you have in mind. WP does not want (for example) an article on every person or object in the world, just ones for which a case of "notability" can be made, and defended if required. The general policy is set out here: https://en.wikipedia.org/wiki/Wikipedia:Notability . In general, if you can find existing WP articles on similar subjects, at the same level of "granularity", then that is an encouraging (but not infallible) rule. Bear in mind that when you create the article, you will need to cite "reliable" external sources for the information that, by implication, also consider the subject "notable" (an entry in another encyclopedia is a good start).

Next, think of the best title for your proposed article, bearing in mind that WP is for a general, not specialist, audience. If not obvious that the title is a song, you might like to add the suffix "(song)", for example.

Next, search WP for your desired title. E.g. if you do a search on the (fictitious) title "The Fishpaste Song" (OK, I just made that up), you will get a message like: "You may create the page "The Fishpaste Song", but consider checking the search results below to see whether the topic is already covered." If you click on the search term in that sentence - now highlighted in red, to show it is presented as a link that does not yet exist - you will get to an edit form that will allow you to create the page and save it as a new article.

To see the style of WP text behind-the-scenes, go to another article that resembles yours in as many respects as possible and click on "edit". This will show you the WP conventions and code which make *that* article look like it does. (Of course different editors can do things in different ways so there may be some variation between styles - hopefully you have picked a good one).

Once your article is complete - with cited sources, no direct plagiarism, and other things to keep the WP community happy - you can save it (best to do a "Preview" first and fix any errors) and it goes live straightaway. It will then appear on a list of "articles for review" and will then get reviewed at some point - e.g. typically around a month in my experience - by an editor who may change it, improve it, or (a couple of times for me) enter a discussion about the article's notability or lack thereof, on the article's talk page. Sometimes this gets a bit picky or heated, especially if the notability is a bit arguable or borderline in some people's view. For example I had a problem with a tetchy editor on my page on the Australian guitarist Ian Date, see https://en.wikipedia.org/wiki/Talk:Ian_Date - he deleted my discography (evidence of notability) on a pretext, and then claimed the subject was not notable. So, sometimes you have to get into an argument, and also accept the possibility you may lose as well, and have to walk away. But I have not lost yet...

So there is my sage advice for now. To see a full list of my articles, edits and other contributions - some better than others - you can go to https://en.wikipedia.org/wiki/User:Tony_1212 .

Just bear in mind that engagement with Wikipedia is a little bit involved (learning the syntax, principles etc.) so is only really worthwhile if you plan to carry on as a contributor, at least for a few articles. You can always walk away but it does require commitment of a bit of time, especially if you want to keep track of articles and discussions arising, and participate in attempts to improve them over time.

Good luck! - Tony