Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

We are listed on about 6 sites and besides the typical Airbnb and VRBO, we've had success with Travelstayion as well. 

Also, if you goal is to continue scaling, a real estate CPA could be a great resource for accounting and tools like DSCR loans can help your grow quickly, especially for cash-flowing properties. 

Reach out to @Tom Gimer at Eastern Title  Agreed Tom is / will be a good resource for higher level financing closings.

You can take advantage of the free resources here like the BP podcasts and forums.

I don't really come on this site much anymore.

I do have a property manager on-site to address any concerns my tenants have. 

There are training sessions you can sign up for on the site, these are live with no recording of the sessions. 

I’d also love any recommendations for beginner-friendly books, podcasts, or other resources that are suitable for a teenager. 

Quote from @Adriana V Alvarado: Hi everyone, I am just starting out in real estateEveryone has different ideas , goals, and resources but most people would probably tell you not to invest for rental in bay area.