You can find the AI player settings in the BP_AIPlayer blueprint’s Class Defaults.

Here you can edit the AI’s settings, You can set the starting resource by changing the values in the Resources setting.

Number of Defence Unites is the number of units that the AI will always keep at its base to protect the buildings and non combat units.

Max Units is the starting max units for this AI player, then there is Max Units Max this is the total max units the AI is allowed to have.