I would suggest going to Home Depot or other hardware stores and looking for 18 gauge two wire thermostat wires. It comes in spools up to 250' long, and will work well for your application. If you only need about 20' of wire, check to see if you can buy something in a smaller spool.
Then install a switch that is where you want it. Bring in power from another light, and to the switch, then to the light strip with the new wire. At the start of the light switch, hook up your red and white wires to the slight strip. If it fails to light, check for 12 volt power, and reverse the two wires if required, it might be working in the reverse polarity.
You can search for the light strips here.
AliExpress.com Search 5050 light strip. I also found some 5050 24 LED panels at the same place, $2 each when you buy 25 at a time. This was plenty to convert all my normally used light fixtures, and the porch light - I used 4 panels there, and have a super bright light that only uses 6 watts!
Fred.