That, by video standards, is ancient and very under-powered. With resizing 4k to 1080 and very little else ... yea, I wouldn't be surprised that a rig with only 8GB of RAM and the old Intel HD graphics is working pretty slow.
The laptop is very weak. That beig said it would be best to have a 4K sequence and render to 1080P. You might be able to edit 4K at 1/8 resolution or you might not. If you cannot then you will have to drop the 4K video into a 1080P sequence. You might have to edit at 1/2 or 1/4 resolution.