Not sure how you could have "new" boxes of tulips and narcissus at this time of the year. If the bulbs are firm and don't have any sign of mold, you can plant them now. They may not bloom next spring, but if you mark the bed where you plant them, you will know if they send up any leaves. It might take a couple of seasons for any flowers to appear. I wouldn't recommend you add any fertilizer at this time of the year as they should remain dormant now, but do add lots of compost to the planting bed.
You should plant your iris now as well. Don't expect any flowers for at least 2 to 3 years.
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.