Good luck with your next try.

Fungus gnats are attracted by vinegar, especially apple cider vinegar.

What you can do is fill a dish with some vinegar en use a flytrap nearby. I use sundew ( carnivorious plants ) with sticky traps , they catch about 20 flies each day. I just put the carnivorious plant near the vinegar. sticky paper could also work.

Also alot of commercial natural pesticides that are based on fatty acids will also kill fungus gnats if you spray them on the surface. Those pesticides break down and can be a feeding ground for fungi, so you can only use it on older seedlings that don't need a cover.

very easy species to germinate and care for are eucalyptus dalrympleana, parvula, aggregata. these don't need a stratification period, the seeds of aggregata and parvula have a long shelf life while most other species have a shorter shelf life and have to be either fresh and sown immediately.