There are no dumb questions, so relax bro. ✌🏻
Considering your current storage need for about 3-4TB, you can go for a 2-bay NAS like Synology 223J, but if you want expandability, you can go with Synology 723+ which is also 2 bay NAS, but in future you can buy another device and connect and expand to 7 disks.
Or you can go for Synology 423 which is a 4 bay NAS, you don't have to populate all drives at the same time. You can keep on increasing the drives later as well.
The reason I recommend Synology is that it's easy to get set up and their UI is also very simple and friendly. But if you just want to have a storage solution, Qnap and Asustor are also good options to consider.
The cost of NAS is something that increases over time, for example, if you buy a 4 bay nas, you can get it for like 35-37K, that's diskless, but then you want to add HDDs, so a single 4TB would cost about 10K, so when you have 2 disks, that's another 20K there, then there is cost for Cache drive which should be an M.2 NAS.
Also, keep in mind, because for reliability, we enable RAID, that allows us to loose a drive or two but still be able to access data. Which means because of this, you will loose capacity. For example, even though I have 2x 8TB HDDs, because of redundancy and RAID configuration, I have only 8TB usable data, but that gives me benefit that I can literally go and pull out one drive from my NAS and it will still continue to work flawlessly. So, I would recommend to setup RAID.
Keeping that in mind, either go for a 2 bay nas which can be expanded, or go for a 4 bay nas without expansion.
2 bay without expansion is for a very specific niche.
