To make this super easy, on a loading screen before any practice, qualifying or race. Go to options with menu button, turn difficulty down to very easy and start the weekend.
Have a few practice sessions to get yourself used to the track, and once your confident, go into qualifying.
If the difficulty is set to very easy, the time second place will achieve is around a 1:31.5 (At best), so the lap time you need is a 1:30 or low 1:31s to get your maiden pole position and this achievement