I got a determination letter in the mail today from employment. What do I need to do now to get it

Get what? Determination about what? You need to be more detailed if you expect us to help.

I got a determination letter from the unemployment office. It doesn't make sense.

Please provide more information into your situation. Were you working? If so, for how long. What is your location as laws vary by area. Were you fired or laid off?

To give you the proper advice we need as much information as possible.

You didn't learn the first time that you need to provide more details? What about the letter doesn't make sense? A determination letter from unemployment insurance generally states whether you are eligible to receive unemployment or not.

You always get a letter, it either says you are going to get benefits are you are not.
** if you are going to get them, nothing more has to be done.

If you are not going to get them, it will tell you of your rights to appeal.