I've already written several games in it, of various types, and don't have a great troubles with using the program. I'm just struggling with RTS specific things such as pathing* and AI and am looking for some general tutorials on writing these kind of functions.
*Game Develop already has A* search implemented, but I wanted to look at other searches and how to go about implementing them.
What you want is a course on algorithms. You need to learn about things like Big O Notation, search pattern algorithms, mutating algorithms, etc (if you want to have top notch stuff that is).
If you're a united states citizen you might want to check out some of MIT's online cources, particularily the 6.00 courses. The course is in python, but python is easy to learn as you go, and the information in those courses are probably right up your alley.
edit : if you want a cheat on pathing, google a* algortihm
IIRC MIT made its courses exclusively available to US citizens, so the site checks for the location of your IP address before allowing you see content. The only ways you can view the courses is if you're computer is located in the states, or if you have a US proxy you can use.