The basic "rules" are...

the song must be original OR you have to have purchased the license to cover the song.....

You must have used one or more PG products in the recording process/chain to have created the song.

Once you satisfy both of those "rules" then feel free to post in the showcase. If you want specific feedback, on, for example, the mix quality, or some other thing, be sure to ask about that and make it clear you want that sort of feedback.

Generally, I have thought of the Showcase as the place for finished songs. If you have a mix in progress, something you're still tweeking of struggling with..... the Recording, Mixing, Performance, & Production forum might be a better place to ask for the feedback on those topics and issues.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.