What type of weeds are these?

[DerbyDale]

I'm new to trying to get a great lawn. I renovated my lawn last year and it's looking really good so far, except for a few weeds here and there. I applied Scotts Weed n Feed a couple weeks ago, but can't tell if its working yet (other than greening up the lawn really well). I would like to ID the weeds I have, so I know how best to fight them.

Thanks for any help.

Weed 1:


Weed 2:


Weed 3: