We have little blue flowers amongst our grass. What is it and what ca

Might be Creeping Charlie.

I also suffered with Creeping Charlie! At one point, two thirds of my lawn was taken over. I tried everything under the sun. I finally tried Spectracide Weed and Feed. I mixed a much stronger solution than the instructions said. Used a handheld sprayer and really wet the "lawn" down with no rain scheduled for the next few days. Killed the Charlie and he lawn came back stronger than ever. I still get some Charlie coming back every so often, so I pull out what I can and spot spray it along with other weeds as general maintenance.

Does it look like thishttps://byf.unl.edu/wild-violet-control

they could be wild violets; if you don't like them you would have to use some sort of weed killer.

You can use lawn weed and fertilizer from many places such as walmart. It kills weeds and feeds the lawns.