Sow the seed in mid September.* It will take about 6 years or more for the bulb to develop and then flower.* This should be helpful.
You don't say which variety of tulip this is, but if it's a hybrid you won't get the same plant from the seed.* I let my species tulips go to seed so I'll have more and more each year.* This should be interesting for you too.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.