Juan,
in an Airbus if you PRESS one of the autopilot knobs, you tell the aircraft to use “managed mode”, basically what you fed into the flight computers for routing and performance. If you PULL the knobs you tell it to use “selected mode”, what you dialed in the boxes. If there is a dot int he boxes it’s “managed”, if there is no dot it’s “selected”.
I recommend you watch some youtube vids about the topic, it’s a bit too much to simply write down in a forum post. Go step by step.