Sometimes persuading a new roll of filament to go through an extruder can be a bit of a pain. Here is how to quickly straighten and feed it.
Wave a lighter flame under the filament for a few seconds about 20mm from the end. Stretch the filament a bit while it is warm as shown - do not snap it as the end will then curl. Allow to cool, blow, or use burnt finger as heatsink.
Trim end to a stout point. This will now easily feed through most extruder mechanisms.