You're probably facing something like an Outpost, right?
https://www.elitedangerous.com/galaxy/starports/
If you don't see your pad at first, fly around it to the other side of the squarish blocky looking section and you'll find it eventually.
Oh, sorry, I didn't read that you're on the
Training Docking Mission.
The destination for this mission is a Coriolis-type (Cuboid shaped) station, IIRC.
https://www.elitedangerous.com/galaxy/starports/
You want to find the square face that has the white blinking lights at the corners. That's the face with the port entry, or "mail slot" that you want to fly into to find your landing pad.
If you see a square face that has red blinking lights, that's the opposite side of the station.
After you request docking with the station, you will see the holo depiction of the station on your dashboard. This holo model comes with an arrow pointing to the side with the mail slot.
Also, as others have said, the mail slot on these and other stations always faces towards the planet.