Short answer re the Spanish military? Minimal.
When the restored kingdom of Spain mounted their attempted "reconquest" of Spanish America in 1814 under Lt. Gen. Pablo Morillo, the grand total (officers and men) amounted to 10,640 men, in 42 transports and escorted by 18 warships.
To reconquer a continent.
And half of another.
Even before the Napoleonic wars broke out, Spain garrisoned the Empire on a shoestring, with a mix of "royal" regiments recruited in the Peninsula itself and the Americas, plus various local, militia, and irregular forces.
Officers were invariably white (and usually peninsulares, rather than criollos); ncos and enlisted tended to be mestizo, although depending on a given units' recruitment point, might include rank and file up and down the "casta" spectrum, including - in some locations - men of purely aboriginal or African ancestry.
Naval squadrons were small as well.
As an example, at Pensacola in 1781, the Spanish expeditionary force numbered all of 7,000 men, regulars and militia - and that was about the strongest single "Spanish" field army before Morillo's force arrived, 30-odd years later.
Best,