Have image now what?

I installed Docker for Windows and built then pushed the example cheers2019. I want a container called crops/yocto so I:
docker pull crops/yocto:ubuntu-18.04-base
now when I do:
PS D:> docker images
airheadbit/cheers2019 latest 88c14453f8ed 3 hours ago 4.01MB
ef7bea6bbd8f 3 hours ago 356MB
crops/yocto ubuntu-18.04-base dc40482353f3 5 days ago 802MB
golang 1.11-alpine e116d2efa2ab 5 months ago 312MB

I can see that I have the image so how do I USE IT?
I tried:
PS D:> docker start crops/yocto:ubuntu-18.04-base
Error response from daemon: No such container: crops/yocto:ubuntu-18.04-base
Error: failed to start containers: crops/yocto:ubuntu-18.04-base

PS D:> docker build crops/yocto:ubuntu-18.04-base
unable to prepare context: path “crops/yocto:ubuntu-18.04-base” not found

What have I missed? Do I need a “WORKSPACE” or a VOLUME??? before cloning?