How long do i wait for the 1099 in the mail or can I just file for it without the 1099?

Before filing without having received the Form 1099, you should first check with whomever was going to issue you the Form.  Depending upon what kind of settlement it was, it may or may not be taxable.  If it is taxable, it should be reported whether or not your receive a Form 1099. 

What is it's a severance settlement?

Normally a severance settlement would be reported on your W2.  I would suggest checking your W2 to see if it is included in your box 1 wages.  If you have not received it yet, it will included in income in the year received.  If you have received it in 2020, contact your HR department to find out the tax reporting of the severance.

The pandemic has affected your taxes in many ways. Including reporting in TurboTax the amount of stimulus money you received. Click Here for more information on how the Pandemic affected your 2020  taxes.

I would think you could simply go on-line to the provider (e.g., a brokerage house)... often electronically  importing or downloading as a PDF. Most have been produced by mid-February.