best gaming laptop in budget on market right for video editing

HP ZBook 15V G5 Core i7-8750H 16GB 256GB SSD + 16GB Optane 15.6 Inch Quadro P600 Windows 10 Pro Mobi

https://www.laptopsdirect.co.uk/hp-zbook-15v-g5-core-i7-8750h-16gb-256gb-ssd-16gb-optane-15.6-inch-q...

The graphics is not powerful enough for 4K, among other things.

DELL Inspiron 15 5590 15.6" Laptop - Intel® Core™ i7, 512 GB SSD

https://www.currys.co.uk/gbuk/computing/laptops/laptops/dell-inspiron-15-5590-15-6-laptop-intel-core...

There is not enough RAM to run well even on the most simple projects and media and the graphics is not powerful enough for 4K, among other things.

Moved to the Video Hardware forum.

That's not the most ideal machine for editing; it doesn't have the fastest processor and it only has an integrated GPU, which I do not recommend for editing and graphics, and certainly not for dealing with 4K material. You're going to want a dedicated graphics card if you can get it.

You're also paying for a touch screen here, so I would trade that for higher specs. 

Also, do not underestimate how much storage and processing power 4K requires. If you don't need to be working in 4K I don't reccomend that you do. It has 4x as many pixels as HD, not twice as many, and it requires significantly more processing power, especially if you're working with a highly compressed format. Proxies are great, but they take up storage, so 512 GB might not be enough storage for all of your files. You always have to consider your tradeoffs. Highly compressed formats take up much less space, but they require a lot more processing power to decode vs intermediate formats which are much easier to edit, but take up more storage.

Something else to consider is that Intel has a technology in its processors called Quick Sync which makes encoding and decoding H.264 significantly faster when the new "Hardware Encoding" feature is enabled in Premiere or AME: https://helpx.adobe.com/x-productkb/multi/gpu-acceleration-and-hardware-encoding.html#HardwareacceleratedEncodingDecodingIntelQuickSync

This feature is only supported by Intel processors with QuickSync, not AMD ones.

So that, coupled with the strong recommendation for a dedicated GPU, and the question of whether you really "need" 4K means you might have to make some tradeoffs in your expectations, whether those are regarding price or performance, 

"In budget" is relative. Could you provide a budget range, as well as what type of footage you will be editing?

HD requires far less processing power than 4K to edit.

Do you need a lot of internal storage or do you have a fast external drive? You don't want to be editing off of a USB 2 drive, so this would have an impact on what gets chosen.

Do you use a lot of effects that rely on the GPU, such as color grading?

There's a lot to consider here, but without any idea what your budget it, how you work, and how you want to grow with this machine, nobody will be able to give you good advice.