Simply put all three packages to the catkin_ws/src directory and run
catkin_make
from catkin_ws directory. This should build all the packages without problems!
First you need to launch the world simulation with
roslaunch my_robot world.launch
Then you need to launch RTAB SLAM node with
roslaunch my_robot mapping.launch
And you're good to go!
You can run keyboard teleop node to control the robot manualy with
rosrun teleop_twist_keyboard teleop_twist_keyboard
Can be found on googlde drive https://drive.google.com/file/d/1qmboehoJe7ap-ZPlH_KcBJF5xaLCP8Mm/view?usp=sharing
Sometimes gazebo just crashes - simply relaunch it.