Welcome to the Apple Support Communities! I see that you want to create a calendar event with reminders, that repeats ONLY on weekdays. I have events like this, myself, and I would be happy to help.
- Open your iOS Calendar App
- Tap the + symbol in the upper right corner
- Set the title, location, date, time, etc.
- Tap "Repeat", tap "Custom" (at the bottom)
- Tap "Frequency", then select "Weekly"
- Tap the days Monday through Friday to select them (you will see a check mark)
- Tap "< Repeat" in the upper left corner to go back
- Tap "< New Event" in the upper left corner to go back again
- Add other details of the event, like "End Repeat", which calendar it's on, etc.
- Tap "Alert" and "Second Alert" to set when you would like to be notified about the event
- Tap "Add" in the upper right corner to save the new event
Have a wonderful day.