I don't know how to work on my carburetor and I haven't been able to find a new one. I have a d150 with a 6 cylinder 4 speed. Carburetor is moving around and doesn't want to start.

 

Bolt it back down?

 

So much missing info here ..... did it work before then just started acting up?
What do you mean by "moving around"? ..... Are you talking about the idle fluctuating around .... or is the carb physically moving around?

Carburetors can usually be repaired at home with some basic tools and a rebuild kit .... often you can find a video online for a carb similar to yours.
Need more info on what your issue is in order to help.

Often the carburetor gets a bad reputation because people do not understand them, so they automatically point the finger at the carb because it "doesn't want to start"

You can remove the carburetor and drip gas into the intake and start the engine with no carburetor on it .... will run terrible, but the engine will start.
So if your engine does not want to start, you do need to verify it is getting fuel. Pour some gas into the carburetor and see if it starts then.
If it does not, then you need to check the basics like spark and timing.

Assuming fuel delivery is fine, float is stuck closed .... then the carburetor would prevent the engine from starting .... If the carburetor was literally loose, then it would suck in to much air making it hard to start. ..... If the choke was stuck open, would make it hard to start when cold.

Just pointing out there are a few things that we can point to on starting issues caused by the carburetor .... most carb issues are drive-ability issues .... does not idle, stumbles .... accelerates poorly. They are not no start issues.