SSD upgrade

[Akdeniz52]

I have a HP Pavilion Gaming Laptop 16-a0018nt (3Y4V0EA) .I want to upgrade my computer's ssd and I don't know if this computer has an extra ssd slot or not. I also want to ask which type of ssd is suitable for this computer (m2.sata, m2.nvme etc).

[Huffer]

2280 form factor NVME M.2 SSD. 

Service Manual 

It only has one M.2 slot but could also have a 2.5 inch SATA SSD or HDD at the same time. Since your laptop only came with an M.2 SSD, you probably do not have mounting hardware for a 2.5 inch disk. If you want more storage space you are better off getting, say a 2 TB M.2 SSD rather then incurring the expense for the 2.5 inch disk and the hardware, which can also be hard to locate. 

[Akdeniz52]

So I only have 1 storage space and I currently have an M2 SSD installed. If I want more storage space I need to buy a new SSD and remove the previous one, am I right?

[Huffer]

As a practical matter yes. You could locate and buy the cable and bracket used to mount a 2.5 inch SATA SSD or HDD in the laptop but these parts are hard to locate and can be expensive. A new, larger capacity M.2 SSD is the better option.