I am good in rc planes but not perfect so i decided to start with multirotors
Ok, Sounds good!
you should split your project in 2 phases
1) Build Quad
2) Then set it up for auto navigation
For building multirotor you can use cheap board from HK for auto navigation you will need more advanced board like APM 2.5 or DGI .
also search forum for build logs ..it help you a lot.