Go to one of the local hardware stores and ask for a list of referrals - they may have several contractors, some GC's and several trade contractors like plumbers, etc. that their customers have given positive feedback on, and work in your local market.

Go up and see what her apartment reads at, if she doesn't have a thermostat you can buy one at hardware store. 

There are backwater valve for gravity systems fairly inexpensive from the hardware store, however, it can get expensive. 

But for young people interested in getting into real estate who need to start learning about frugality and the ins and outs of general finance, I always use Nerd Wallet (a website) to look for the best reviews on things like savings accounts or credit card reviews, they are great with explaining personal finance.

Suffice it say, everyone's hands will be reaching for your wallet. 

Stay away from the “guru” sales-pitch events - they rarely increase your investment knowledge, they merely empty your wallet!

There was also a house behind the New Ace hardware in Eureka where the seller would carry the note.

The varibles are the hardware and labor costs.Yet, there are so many varible that influence insurance costs, giving a quick call to an insurance agent, who is really your business partner, can be worth the time.

Even just a job stocking shelves at HD, Lowes or a local hardware store can get you some experience in materials and maybe help you meet local contractors and property managers and owners.BTW you are only 15 so make sure you still have fun and enjoy life a little too!

Stay away from the “guru” sales-pitch events - they rarely increase your investment knowledge, they merely empty your wallet!