Will it be difficult to use and understand Linux?
Use? No.
Understand? That depends mostly on whether you can accept that many things work completely differently, even if some things work the same.
If you expect your Windows experience to carry your efforts in Linux, you will be disappointed.
The community is not a company, so you are not a client or a customer. If you want help, you must show your own effort first, and be willing to follow the advice. Usually this means finding a repeatable test case, extracting log files, and so on. If you demand anything, you will be laughed at. Even commercial distros like Ubuntu rely on volunteer community efforts. The community is only interested in getting the tools and programs they use to work well, so they really do not care if you use Linux or Windows or something else; threatening to go back to Windows if nobody helps will be met with derision. You only matter, if you contribute yourself. (Finding a bug, and reporting it well enough so devs can reproduce and analyse it, is an excellent way to contribute, though. All non-asshole developers really do appreciate those.)
If you start with the understanding that Linux is fundamentally (structurally, design-wise) different, and want to learn how it works, and how to make it conform to your own needs (instead of the opposite), I believe you'll have an interesting time. There is lots to learn, so it'll take time, but it isn't hard/difficult; just different. Often, things that
seem to work the same on the surface, have quite important differences in how they are actually implemented. For example, there is no single Linux (or GNU/Linux) graphical user interface; I personally use Gnome, Xfce, and LXDE, but there are also KDE Plasma, Cinnamon, Unity, Mate, and a few others to choose from.
(One fallacy I see often is a claim that Linux is based on command line. That is not true: even terminals are just userspace services.
gettys for console terminals,
openssh etc. for network terminals,
xterm/
gnome-terminal etc. for GUI terminal windows. When you get a terminal, you can use any shell ("command line interpreter") you want, although Bash is the most common one. You can even replace the entire userspace with your own program or shell script, by writing your own
init. This means that even "command line" is optional!)
In my own experience, those who expect computers and applications to work like Windows does, will have problems. Those who have an open mind, only need time and effort. It is just a tool that anyone can learn (given time and effort), nothing secret: everything you wish to know is publicly available on the net. If you have used Mac OS or other non-Windows systems, you are likely already aware of the differences at the subconscious level, and it will be easier to adjust.
This also means that if you don't really have the time, and just want things to work like they do in Windows, you'd better stay with Windows, as you can be more productive there.