Adobe Premiere Pro Timeline Freezing

Have you tried resetting preferences and/or reseting your workspace?
Reset your preferences by holding shift+alt (or option) when you launch Premiere

Please use the free MediaInfo and post a screenshot the properties of your media in tree view:
https://mediaarea.net/en/MediaInfo

Many users are having issues with VFR. If the file is variable frame rate, use Hand brake to convert to constant frame rate:
https://handbrake.fr/downloads.php
Here is a tutorial:
https://www.youtube.com/watch?time_continue=34&v=xlvxgVREX-Y

Exactly what is INSIDE the video you are editing?
Report back with the codec details of your file, use the program below
Free program to get file information for PC/Mac http://mediaarea.net/en/MediaInfo/Download
- when you analyze your file in MediaInfo and post a screen shot in the forum, do so in TREE view