Yeah so like others have said break it down into chunks then do a bit at a time.
So first you woul need to spawn them into the world. Notlrmally in rts games this would be done by clicking on a building or adding them to a que with a build timer . When the timer hits zero you would spawn the unit at the building location with an offset .
Next you would need to select the unit and move it to the resource location. This is normally done by tracking the mouse curser position and then doing a line cast to see what it hits.
Once it reaches the destination to gather the resources would again probably involve you clicking on the unit then clicking on the resource wish to gather.
The actual gathering would then just be a looped animation .
Or if you wanted the build unit to build something at the location you would have to perform you’re checks. Then spawn the object you want to build and most likely destroy the original unit and play another animation