I want to start with YouTube. I've been a bit smart and many say it's not too late to start using YouTube. Of course I do not have any equipment at the beginning. Here we come to my first question, I have 100 euro and want to know what I should buy at the beginning? In addition, my channel is also a topic and I have no idea which is best at the present time. I own a Playstation (i.e., lets plays are no problem) and I own a Huawei P10 (Leica camera) which is also very good.
Would buy with the 100 euro either a good headset / microphone or save.
I was a little smart
That was obviously not enough. You are still missing 95%.
It is never too late to start with Youtube. Today, Youtube is being used more than ever before.
Which topic it should be, is entirely up to you. If you use a topic just because you think there are a lot of people on it, you notice that in the content you're going to deliver. At the same time, it should also be something that interests people. And you have to be able to stick out. For example, just playing Fortnite letsplayen becomes a mega-heavy thing because so many people do it. But if you can combine that with something that people can benefit from, then things will look different, because then people will have a reason to get your content in.
In terms of equipment, buying a capture card is best if you want to letplay console games. Something like Elgato HD 60 https://www.elgato.com/de/gaming/game-capture-hd60 which is needed for from 80 euro, 60 euro if you're lucky.
Of course, you need something that takes your voice well. A headset is best, and even there it should not be the least valuable.
If you can then buy a good software (something like Sony Vegas) or something, you are well prepared. Sony Vegas is always on offer for 20 euro or so. I got it on humblebundle.com for example.
Hope I could help you.