Attitude and consciousness are mental requirements. Actions are what counts.

Is reality just a collection of facts? No. Any fact is a fact of reality. Any collection of facts likewise. Facts are information, and information about reality is not the same as reality itself, no matter how large the collection.

Does attitude/consciousness determine outcomes? Sometimes. Conscious beings can control certain outcomes, such as what one has for breakfast. For example, once you place a vase in a specific location, the fact that the vase is in that location is an outcome of your conscious intent and subsequent conscious behavior to fulfill that intent.

What does the question mean? What does "just a collection" mean? What "outcomes" are you talking about?

Reality is everything that is, including both physical reality and consciousness. Everything is what it is and acts according to its nature. Consciousness does not change that. Consciousness is awareness of reality. You choose to act in accordance with what you are and what you are capable of by your nature, which does not include overriding the law of causality. See Ayn Rand's "The Metaphysical Versus the Man-Made".

As Ayn Rand stated reality exists. However as the mathematician, Godel, proved math is open ended. There will always be new forms of math and as those new forms of math are applied to our understanding of the universe, our attitudes and consciousness will change.

An old colleague used to say-
You can believe from the bottom of your heart that the law of gravity is only a mental construct, but if you jump off the top of a 10 story building you will end up a hamburger.
That means that existence is independent of human thought.

Reality is a collection of entities with certain attributes, that act, change and exist in certain relationships with each other.

In the context of speaking of these constituents of reality as potentially knowable by our consciousness, we call specific sets of entities, actions, relationships, etc, "facts."

Consciousness can help shape outcomes of those entities or processes that it has specific causal connections with. (Like the movement of your arm and the things that movement affects.) But consciousness can't make just anything happen by thinking, wishing or hoping.

Reality is existence, the physical and natural laws. This is the only truth; facts should follow those truths...in so far as we understand them. So Yes, attitude and conscious intent produces an outcome. Whether that outcome is good or bad would depend upon one's use of or rejection of those truths and facts related to reality.
However, much of the culture today is in denial of reality.

Existence Exists.
A=A
Mysticism/Magic can't be measured or always repeated.