I just got a home inspection in CA done for $500 on a lot with two units on it.

She is requesting I show her the home inspection report I paid $500 for.

Based on this information you will know if the property would be worth the effort, ie if the cost to rehab exceeds the value or if there is enough equity you may be able to refinance the property pay the back taxes and get funds to rehab the property.Then I would suggest you get a home inspection that would give you a unbiased professional opinion of the work to be completed.

The inspection found a few items that need to be fixed.

I plan to have a structural engineer inspect and make a plan.

You may need to file documents with the city to let them know it isn't a primary residence (tax purposes) and they may require rental registration and/or inspections. 

@Andrew HaneyNational Property InspectionsBrady Home Inspections Those are my go too choices.

Here is what I am seeing in the Gatlinburg market:  The buyers generally right now are "all cash", and they are waiving inspections and appraisals so that they can get a deal done quickly. 

We agreed subject to inspection and them removing the lower unit tenants so we could live there.

During inspections check everything and have bids on the items you mentioned plumb/electric/furnace, these need to be professionally done.