The hip-hop mogul is hosting the debut event Saturday, and he's been documenting all the goings-on on his social media ... right from the crack of dawn, when preparations were getting underway and sweet luxury rides were being rolled in one by one.

As the day crept on, more and more people started showing up ... along with their novelty whips, including classic 20th century cars, low riders, monster trucks, Jeeps and just about everything in between. This is in addition to what RR himself was bringing to the table.

We won't list everything he's got in his own garage ... but safe to say, a lot of what you're seeing here is Renzel's, and his selection runs the gamut for gear heads everywhere.

This is essentially an expo right there in Fayetteville ... and it's all happening on Rick's massive property, which is part ranch and part compound. He's got acres of land to spare, and it looks like he's putting all of that space to good use -- there appears to be several dozens of vehicles strewn about the grounds, and just as many people (if not more).

He told us this past week on 'TMZ Live' that he would even be looking to buy some stuff that caught his eye ... and we imagine he's been busy scoping out the hardware being trotted in.

Or course, there's a competition element to this as well ... and if you peep Rick's IG Story ... you'll see he's already dishing out some iced-out chains as rewards for the best showcases.

Looks like a good ass time, and considering just how massive of a turnout it conjured ... something tells us this will be a sure thing year after year, and may even grow. Shoot, the guy is liable to get some sponsorship looks ... because all kinds of wheels on display here.