Couple area rugs and its good to go. 

BUT HERE IS THE KICKER :(The hallways and rugs (out of my control ) have not been touched in 20 years.

Even in Bedrooms - if they want a soft surface, tenants can put down an area rug.

Your carpets are expensive and the last thing you will want is to have a company cleaning your rugs that doesn’t know what they are doing.The next thing you will want to look into when you are hiring a cleaning company is if they are licensed and insured.

In my lease the tenant has to have carpet professionally cleaned when they leave and provide a receipt (no Rug Doctors).

If the tenant is embarrassed about the current carpeting, suggest they get large throw rugs to cover them up.  

If you choose too rugged a project, it won’t qualify for a traditional mortgage.  

Please take into account that I am somewhat of a newbie so I prefer to invest my money into things like rugs and lampshades

It would just be masking it, like sweeping the dirt under the rug. 

She told me to return a rug I got for under $50 at Ross then later bought a ridiculously shaggy one that was difficult to clean for 3x the price at Home Depot.