Abel chose of his own will to offer a sacrifice to God and through it obtained witness that he was righteous (Hebrews 11:4).
Noah chose of his own will to build an ark for the saving of his household in obedience to God (Hebrews 11:7).
Abraham chose of his own will to obey God by going to a new land that God had yet to show him, not even knowing where he was going (Hebrews 11:8).
Moses chose of his own will to suffer the reproach of Christ rather than to enjoy the passing pleasures of sin (Hebrews 11:24-26).
We most definitely can voluntarily choose to turn to God of our own will.
However, it is important to note that a human's "will" is a created thing. It doesn't exist apart from being carefully crafted, designed, programmed and empowered by God. It has no power "on its own" because it has no existence "on its own". Everything it is and everything it does is because of God's will, God's plan, and God's design.
To make a choice of one's own will simply means that one is not unwilling, or making the choice under forced compulsion. Rather, the choice is made as a result of one's own preferences, inclinations, and desires, all of which were carefully crafted by the God of the universe.
Thus, when our will chooses to turn to God, it is always because God has caused it to do so. Every choice we make is foreordained by the God who made all things (John 1:3; Philippians 2:13; Proverbs 16:4).
According to the Bible, if we do not turn to God, we will be judged and found guilty for our crimes against Him (Romans 3:23; 1 Corinthians 6:9-10). However, if we do turn to God, we will be saved from the wrath that is to come (Romans 6:23; Acts 2:21; 1 Thessalonians 1:10).
It is not too late to place your trust in the God who made you (2 Corinthians 6:2; Romans 10:9-10).