My company recently changed HSA companies. The result is a huge amount on my w2, 12c with a W code. I called the company, and they said a form 1095-c is coming to help

Form 1095-C reports that the employer provided health insurance. 

It is not enter, nor attached to your tax return. 

TurboTax will ask if you had it (had health insurance coverage through your employer) and if you answer "yes" that is the end of that interview. 

Form 1095-C has nothing to do with your HSA. 

You should have received a 1099-SA for the HSA account. 

Yes, TurboTax handles Form 1099-SA. 

Does the amount on your W-2 show an over-contribution for your HSA? 

"For 2024, the annual contribution limits on deductions for HSAs for individuals with self-only coverage is $4,150 (increase of $300) and $8,300 for family coverage (increase of $550). There is an additional contribution amount of $1,000 for taxpayers who are age 55 or older."

IRS link 

Entry of the Form 1095-C into TurboTax will have no effect on the tax treatment of the amount shown with code W in box 12 of your W-2.  See the pot made by KrisD15 regarding the limits on HSA contributions.