Hi is there a FREE video editing software out there that can output in 4K rather than limiting it to 1080 ? My main source would also be 4K.

Check out davinci resolve 16.

Hii,

If you want to edit the video files in the best way then I would like to suggest you to try Stillbon Video Editor SOftware for this. It offers the users to edit the bulk video files at once without any data loss. Users can edit the links, images, watermarks without any hassle as it offers a simple and intuitive GUI interface for both technical and novice users. It retains all the data intact. It enables users to edit the video files taken from any devices such as a camcorder, digital camera, mobile phone, etc. Moreover, it supports all the Windows OS.

For more info visit:-  https://www.stillbonsoftware.com/video-editor/

Kdenlive is popular among Linux users but has also Windows/Mac versions

iMovie is free

TunesKit AceMovi https://acemovi.tuneskit.com/ is free for 4K video editing,  maybe it can meet your needs in video editing