which QNAP NAS model is it?
in qts (which you can access by typing your nas IP:8080 ) or using qfinder utility app to access qts.
then in qts, normally you have icons on the qts desktop page. but if not, click on the left side panel which will pop out more setting icons. app center SHOULD be listed there. its a core setting for qts.
If you want to add appcenter or any of those items to desktop (to make accessing quick), just drag drop them onto the desktop in qts.
there are a lot of introductory and tutorials here if you want to explore what the qnap is capable of
this is one of the tuts to get you started. there are more parts to it, not sure why they didn't just add a proper playlist
here is another
Synchronize files on your computers and NAS with Qsync｜NASpedia
also check the qnap.com site for the download to your qnap model, and get the manual. or on the qnap main page, features to know what the qnap has to offer.
QTS 4.4.1 is a beta firmware. It's best to stick to QTS 4.3.6 which is the latest stable QTS for now. If your QNAP is an older model, you may not be able to use QTS 4.3.6, so just use whatever is the latest for your model.
as a beginner, first thing to know about the qnap is
1. keep backups. qnap or not, always have a backup plan.
2. always update the qnap. but don't just simply update (just like microsoft windows, there have been some bad firmware updates every now and then, it happens), check the forum for other user comments to see if it's stable first. most of the users wait a week or a month before updating. but if it's an urgent patch it's probably better to update sooner. this is an example thread i was speaking of
3. security counselor app in appcenter is an app to quickly check your qnap security settings to optimize it to harden security. I suggest you check that out.
4. if you are running raid on the qnap, go to storage manager and schedule a monthly raid scrub. and set priority for raid sync to either normal or highest priority.
5. file station is the qnap native app for exploring files. it's similar to windows explorer. file station is best for moving files/folders internally with the best performance. If you are moving stuff internally on the qnap, it's best to use the file station. If you are moving very few things, i just use windows explorer instead.
6. as the qnap admin, it's best to keep track of any critical issues that get posted on the qnap advisory board. best if you subscribe to their mailing list for it. anything not mentioned on the board will usually be posted in the forum by other users
7. that left side panel has all the navigatable options for QTS settings. I suggest you explore them to understand what options and features are available. What is not there, would usually be in appcenter, which would require installing an app, which will then add more options via that installed app.
8. qnaps can go EOL at which point they receive security fixes, until they totally end support. Some very old models like my TS-509 pro will no longer receive security patches as of 2020-12 If your qnap is also going to be completely EOL, probably ask your manager to replace the QNAP for a newer model to renew QTS support
9. snapshot feature will offer protection against ransomware.
10. if you need technical support by QNAP, use the helpdesk.
11. hybrid backup sync from appcenter, is the native QNAP backup app. It can do backup to cloud, or RSYNC. there is RTRR but that only works with other QNAPs.
12. setting > shares is where you setup your usable shares to begin storing data. There is also users where you can setup permission rights.
13. storage manager is another important setting. this is where you setup storage, manage storage and also snapshots.
14. resource monitor helps you check your qnap resource load on the NAS.