Do you have any advice for a young Christian such as myself? .....
Believe the scripture that says that "by grace you have been saved through faith".
Beware of any theologian, preacher or teacher who reverses the order.
.......Are there any regrets that you have from your younger days?
Yes.
As a new Christian I listened to a preacher who had the order reversed and came to believe that I was lost every time I did something dirty. I then had to get saved again. Only to be lost again and saved again every so often.
There are many here is this forum who preach that same false gospel.
In time I simply gave up on so called Christianity because the pain of sinning, repenting and getting saved again every so often was no way to live.
I lost 15 good years to the world simply because I misunderstood that I did good works
because I was saved and not in order to get or stay saved.
Understanding the truth has made my walk with the Lord a pleasure for the last 4+ decades.
I have many regrets in my life since coming back to the Lord and I know that some of them will cost me in some way when I meet God face to face. But one thing I do not fear for one moment is that He will not welcome me into His presence with open arms.
I know Whom I have believe and I am persuaded that He is able to keep that which I have entrusted to Him against the day of judgment.
Assuming that your conversion was real and that you have been born again - figure out the simple gospel of grace and run like a scalded cat from anyone who denies it.