karla@karla-Inspiron-5593:~/drone/apm$ cd ardupilot
karla@karla-Inspiron-5593:~/drone/apm/ardupilot$ ls
AntennaTracker benchmarks Dockerfile mk tests
appveyor.yml Blimp docs modules Tools
ArduCopter BUILD.md Doxyfile.in pyproject.toml Vagrantfile
ArduPlane CODE_OF_CONDUCT.md libraries README.md waf
ArduSub COPYING.txt Makefile Rover wscript
karla@karla-Inspiron-5593:~/drone/apm/ardupilot$ cd build
bash: cd: build: No such file or directory
After your commands worked for me, I went to “Connecting MAVProxy to SITL Drone” video, and why I dont have build in my ardupilot file