Where or how do I find out how much I contributed to my HSA from my bank account vs what was employer contributed?

You can determine the amount contributed by your employer based on your W-2.  The Employer contribution will be located in Box 12 with a code W.

Thanks, so if I have $1500 in Box 12 code W and my HSA has "total contributions $2500" then the difference $1000 is what I transferred from my bank account to my HSA?

That would be very likely and best to verify with your bank transactions.  The $1000 is the portion that should appear on form 8889, Health Savings Accounts, Line 2.  The employer portion should not.