Seed germination, Long answer

I have planted perennial seeds such as cone flower, blackeyed susan, and galardia the year that I collected them. Some came up that year and some came up in the spring. The galardia seed ripened quite late, so they were planted late and the tiny plants did not make it through the winter. I should have saved them till spring to plant them. Many of the seeds did come up in the spring and they are fine. The petunias that I had that self sowed mostly came up the following spring but some came up in the fall when the plants dropped them. So if the seeds don't ripen until September or later I would wait until spring.
Tiny seeds need to be sown on the top of the soil or just barely covered and they need to be planted in a very fine mix. They also need to be kept moist. I put a layer of seed starting mix on top of potting soil in the flat and cover the flats with plastic, you could probably use the aquarium. Larger seeds can be covered more so they are easier to keep moist and may not need to be covered, but they must be kept moist.
Some seeds need a cold period before they will germinate so you really need to get info on each specific species.
My perennials I now plant in flats late in the fall and let them come up in the spring.