Whenever we talk about plants and gardening we need to know where you are situated geographically. Without knowing your climate and temperatures we can't say whether your seedlings are doing well or not. In my climate three weeks for germination would not be unusual. For the same reason, and also because we don't know what species you have, we can't say when they'll bloom.

They look ok from what I can see but can I ask if you are watering with a fine rose or just a spout? The reason I ask is that it looks as if you might have washed the seeds around which would disturb them.

eta, sorry, I didn't notice California in the heading. But even so that's a big place with different climates.

It depends on what kind of seeds they are. Different plants have different rates of germination.