What is a 5329 t and what is line 49 I never got this form

Form 5329 is a form on which additional taxes on tax-favored accounts (like IRAS, HSAs, and the like) are calculated as needed. Line 49 of the 5329 is the amount of additional tax assessed because of excess contributions to an HSA.

An HSA is a "Health Savings Account". It is a persistent, tax-favored account that enables taxpayers who have coverage from a High Deductible Health Plan to pay for the deductible with tax-advantaged dollars. Only taxpayers who are covered by a High Deductible Health Plan (normally, but not necessarily provided by an employer) are allowed to contribute to an HSA.

Note that you may not have conflicting health coverage, however, or else it is as if you did not have HDHP coverage at all. Examples of conflicting coverage are Medicare, an HRA, a spouse's health FSA, most other health insurance, and so on. There are only limited types of coverage that do not conflict - these are covered in IRS Publication 969.

Do you have an insurance card? If so, look to see if it says "HDHP" in the fine print. Conversely, you can contact your HR people and ask. At the same time, you can look at your W-2. Is there a code W in box 12? The number here with the code W is the sum of the amounts that your employer has contributed to your HSA plus whatever amounts you contributed by means of payroll deduction.

You say that this is the first time you have been asked to fill out any HSA "stuff" - the odds are good that the HSA processing was triggered by the code W in box 12 on your W-2.