Evolution and old-age theories that support it have nothing concrete to support them.
Believing in the universe being old does not necessarily support evolution.
The waw disjunctive that starts verse 2 of Genesis 1 separates verse one, both logically and chronologically, from the following verses.
Therefore, the Earth, going only by scripture:
Could it be 6,000 years? Yes. The bible doesn't say.
Could it be 10,000 years? Yes. The bible doesn't say.
Could it be 100,000 years? Yes.The bible doesn't say.
Could it be 1,000,000 years? Yes. The bible doesn't say.
Could it be 1,000,000,000 years? Yes. The bible doesn't say.
Could it be 4.5 billion years? Yes. The bible doesn't say.
What it does say is that, according to verse 2, the circumstantial clause, during the time period from the end of verse 1 the beginning of verse 2, the earth remained unformed and unfilled, darkness reigned, and God's Spirit was present.
The earth being "unformed" and "unfilled" precludes any life or evolutionary activity. For however long that period was, the earth remained a lifeless primordial mixture of random elements.
It was not until verse 3, according to the narrative, that God began to form the unformed and fill the unfilled.