The issue here is not "predestination versus free will" as if we had to choose one or the other, but to what degree each plays a role in saving souls.
God, at the beginning, looked down the corridor of time and saw the decisions that we would make to accept or reject His message. He foreknew everything that would ever happen (I Peter 1:2). And the Bible tells us that He established our eternal destiny at that time (Ephesians 1:3-5). God decided our eternal destiny before we ever came to this earth. So from God's frame of reference, we are predestined.
The question is, "What criteria did He use to make that decision?" Did the choices that He knew we would make in this life have any bearing on His decision to save us? We believe that anyone who bases their response on the Bible would have to answer "yes" (Joshua 24:15). The choices that we make for the kingdom of Christ definitely affect our eternal destiny.
No one who believes in the Bible can deny that human free will clearly has a bearing on our salvation (Matthew 23:37). Obviously we cannot even respond to the gospel without His grace. However, even though God is sovereign, He does not capriciously and arbitrarily decide that some are saved and some are damned (Acts 10:34).
A just and loving God will give people an opportunity to decide whether to accept or reject His gospel. Each person is given agency, free will to make a decision for or against. If they will respond and surrender to Him, they can know the peace of eternal life with Him.
Your response to the gospel of the kingdom and allowing God's grace to operate in your life definitely does have a bearing on your eternal destiny. You need to make a commitment that is lasting and true, and you can find eternal peace with Christ through His restored gospel.