Combining clips from videos with different properties and exporting

I am a total newbie so I apologize in advance if this is a silly question.

So I have a few different larger videos with different properties (same format of yuv420p but different frame rate and resolution for example) from which I have grabbed short clips and added to a playlist. I of course did this editing before considering that the videos had different properties and that that may complicate the export…

Is there any way export this playlist as is or do I need to convert the original videos/clips such that all clips in my playlist/timeline have the same properties? I’m guessing I do…

In case it is relevant I am working on a windows 8 machine

Shotcut should convert them to a single format when you export them, although you may find it easier in the future to do some of that ahead of time to match up their frame rates and such for more consistent editing in the future.