Thank you so much for all your answers, I really appreciate it.
As I admit, I have completely no experience and I have no idea what is possible to achieve it. I saw in Banggood cheaper version of this kit, but it lacks some of components may be necessary.
For example, I have no idea if it could be powered my USB cable using universal (phone?) charger. This more expensive kit, called "mega" has at least some kind of charger.
For example, I found a kit called "Geekcreit® UNOR3 Basic Learning Starter Kits Upgrade Version For Arduino" and it has no power unit, just a battery + battery connector. Of course it costs less than "mega", because the price is just £16.45
For me, as the one has no idea what could be achieved, probably it could be sufficient... but buying a simple wall charger could cost £10 or more. I'm not really sure if this saving is good idea... or maybe is a good idea?
I'm aware of some of information given by sellers like those will be fake, as you mentioned "Made in Italy", and I don't really believe in it. I do understand it's not an original product but some sort of clone.
Once more, I must admit to my lack of knowledge, and it's clearly to early for me to ask a question "Why original product is better?" - I understand, could be older version, having older components or being slower than recent original parts / boards.
I will briefly explain, why I'm considering kit instead of separate modules. Reason is simple - lack of knowledge and ideas. Having a kit, I could be in some way directed, like "Ok, I have IR module, so I can build detector or meter, to check a distance from obstacle". Having NFC board and key, I could understand how locks like this works. When I have a set of LED I can create a flashing night lamp etc.
I know, I should answer myself first: "Do I really need it?" - but I don't know an answer. For example, I never liked programming at all, and as an adult person first time I started and independently created a game without any help. Maybe electronics is not for me or maybe if I will achieve something will be much worse than anyone before me achieved in better way. This is something I can't answer myself.
I haven't made my decision yet and this is a reason I came here, asking for help, and finally trying to better understand what I can achieve.
As I mentioned, it's too early to ask for a specific help, as I'm not even sure, what is possible.
For example, using this "mega" kit, I want to build a watch (without a case).
I would like to display (using included matrix display - three lines) some information, like time, date or maybe some sort of simple reminder: "buy a bread today!"
And maybe... maybe... if it could be possible - I want to use some other components, like LED flashing. If I still have some unfinished task (for today) red LED will be flashing and when the task will be completed, I will have to push button or touch NFC controller with key and red LED will stop and green LED will flash, informing me I have no tasks for this day.
It's just an example what I may want and I have no idea if it's achievable.
So could you please tell me, if my idea is realistic or maybe is stupid and on my level is completely out of my (or anyone range)?