Welcome Kazum :)
I have one of those too :-) Unless it's really sunny, they don't get quite hot enough to have stuff germinate evenly - heat loving stuff like tomatoes etc. I am still germinating my toms, peppers and cucumbers in the airing cupboard, then giving them around a week on the warm kitchen windowsill, then moving to a colder windowsill and will move them from there to the mini-greenhouse. Runner beans and french beans would come in this category as well, and also courgettes and pumpkins.
Have germinated lettuce, sweet peas, chives, leeks in the mini-greenhouse though.
No more frosts - lucky you :)
Make sure your greenhouse is weighted down and possibly even tied too, mine blew over in strong winds last week, and at least one other A4Aer has had the same thing happen.
Edit
My sweetcorn did germinate in there though, in a sunny week - they are heat-loving and frost-sensitive too ???