You select an appropriate setting (such as a Youtube preset) and then adjust the details of the settings... may take several tries before you get what you want
What version of Premiere Elements and on what computer operating system is it running?
What is the duration of the Timeline that you want to upload to YouTube? As you know, your file size is exceeding the Premiere Elements built in YouTube feature limit for file size (Premiere Elements 13/13.1, 2.2 GB). Is your Timeline duration greater than 15 minutes?
In order to give you a customize answer - please let us know also what your Premiere Elements project settings are - 1920 x 1080i30 or 1920 x 1080p30 or something else.
If you have Premiere Elements 13/13.1 on Windows 7, 8, or 8.1 64 bit and had a 1080p30 project, then you would export a file to the computer hard drive
with Presets = MP4 H.264 1920 x 1080p30.
There is another MP4 preset there with YouTube in its name, but it offers a lesser default 1280 x 720.
You then upload that file to YouTube at the YouTube web site. But, you need to apply for an extended time account there and use it for your upload of the Premiere Elements created file.
Please review, consider, and supply more information for a customized reply.