I’ve heard from people that if you die and don’t ask for forgiveness before you do then you could go to hell. They applied this to believers as well. I’ve accepted Christ as my savior and rely on him for my salvation but if I pass away without asking for forgiveness for my sins first, will this forfeit my salvation?
You should read your Bible instead of listening to the unsupported opinions of others. In Ephes 1:13-14 Paul wrote the following.
And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit, who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession—to the praise of his glory.
In these verses Paul said when we believed the gospel we were included in Christ and were marked in Him with a seal, the promised Holy Spirit who is a deposit guaranteeing our inheritance.
That means our salvation was guaranteed by the Holy Spirit as soon as we believed. God could make this promise because Jesus took all your sins to the cross (Colossians 2:13-14). As soon as you believed He died for you they were all forgiven.