From First Cause proceed all other things. Therefore:
First Cause can not be multiple, because then there would be principles in operation from outside of them, thus, whatever caused those principles would have to be First Cause.
First Cause would have to be animate because 1/ inanimate (mechanical fact) is governed by principles from outside itself (therefore not First Cause). 2/ Even if one wants to say inanimate First Cause is caused by chance, then they admit to cause from outside itself, (as though Chance could logically cause anything). 3/ Some have said inanimate First Cause could have made itself --what-- according to its programming? --But to say that even God made himself exist is logical nonsense. First Cause simply is. (Even existence "proceeds" from First Cause, and not the other way around). 4/ Some have said that inanimate First Cause could be co-emergent with its principles of operation and existence. While an intriguing thought, even then, the principle of co-emergence is external to its beginnings. (There are also, of course, the complications of just how the co-emergence works --same thing that makes Darwinian evolution hard to understand --just how did complex co-dependent systems work as incomplete? The worst complication, of course, is to show that Existence itself was co-emergent, if there had been no such thing "logically (as in cause-and-effect) before".) 5/ I only mention this because it is true --others have shown that there are many other problems to overcome to claim that First Cause may be inanimate. I am not well versed on all of them.
First Cause would have to be conscious, as animate, for the same reason it cannot be inanimate --if not conscious, it would be subject to principles from outside itself. If someone wants to be smart and say those complex principles and even operational creation itself could be produced from an unconscious (or even unintelligent) animate existence (some have even speculated the universe itself, or universe of universes could be this animate existence) with no reason to do so, they invoke chance accident, or true randomness as causes, which (again) are logically self-contradictory --not to mention that were Chance and Randomness to be real, they would present from outside this supposed unconscious First Cause.
First Cause must logically be omniscient or it is subject to facts from outside itself, (even if it caused those facts far down the chain of cause-and-effect, but did not consider the logical extrapolation of cause-and-effect past a certain point, it is still a fact "returning to it unknown", so to speak), therefore not First Cause after all, since First Cause cannot be subject to facts from outside itself. First Cause is the ONLY totally sovereign, un-caused, independent, source of all other things.