Without seeing the video just taking a guess based on the common issue of creating a sequence that doesn't match the source media.
You have 3 variables to keep in mind when it comes to your video resolution and framerate:
The settings of your Source Media, which are determined at the time of recording.
The settings of your Sequence, which you set up when you create the sequence. (Note that you can have many Sequences inside of a single Project. Each can have different settings.)
The settings of your Output, which you specify on export.
Ideally (or at least, generally), you should have the same settings throughout the process from start to finish as seen in this example:
To make sure you get your sequence settings to match your video source settings there are several ways to do this automatically, o ne of them being to drag your media down to the New Item icon in the Project Panel:
(You can also drag media down to an empty Timeline Panel, or right click on the media and choose New Sequence From Clip.)