[toni-a]

I need to update my laptop, without spending too much money as I can't justify the spending on something non essential, my current laptop has poor screen quality and I am using an external calibrated monitor when editing, which is not very practical.  
I need accurate colors on the screen while staying on a budget, I read 70% Adobe RGB is the minimum  needed, is that OK or should I go higher ?
is 4K screen needed or I am just fine with FHD ?
I don't play games but I don't want DPP and DXO to take ages before loading pictures, I also have tons of photos I browse on my NAS and I want thumbnails to appear instantly  what performance requirements should I ask for aside having plenty of RAM ?

[Klaus]

Define your budget ;-)

I'd say that a reasonable choice would be a Macbook Air M1/M2 w/16GB if you don't want to spend terribly much.

[toni-a]

I would

Define your budget ;-)

let's say I prefer being in the 3000-4000 QAR area unless there's something really worth it
I am not used to apple environment, and I already have licenses for windows software unless the advantages are really obvious

[Klaus]

Without knowing the pricing and availability in your region - what about a Dell Inspiron 16 PLUS:
https://www.dell.com/en-us/shop/dell-laptops/inspiron-16-2-in-1-laptop/spd/inspiron-16-7620-2-in-1-laptop/n27620fkvzs

or a Lenovo Legion 5 Pro:
https://www.lenovo.com/ae/en/laptops/legion-laptops/legion-5-series/Legion-5-Pro-Gen-7-16%E2%80%B3-AMD/p/LEN101G0021

Note: Gaming laptops tend to be good for imaging tasks as well.