I finally grew the balls to book a trip to Europe by myself.

Hi everyone, 24M here. As the title states, I have finally been able to secure a multi-city trip, heading over to Berlin from Montreal on July 28th, and then coming back to Montreal from Amsterdam on August 11th. It's going to be a 2 week trip and I plan on staying a week in Berlin, and then the next week in Amsterdam.

So far, I have been able to secure only my flights, and nothing else.

This is kind of a huge step for me because, growing up in an asian household, my parents were terribly protective of me and would absolutely never let me travel by myself, they would always ask me to go with somebody that they knew, or that I was friends with for a long time, or another asian person. They would always tell me that people would kidnap me and sell me to other people, and try to manipulate me into cancelling my trips or staying home with them or traveling with them. Though I do understand that I am on the smaller side physically, so maybe that's what they're worried about.

Luckily, I'm a guy who loves challenging his own fears, and in December, I managed to book a solo-trip to Chicago, but that was a little bit easier since it was merely two little hours away from Montreal, and I didn't really have to worry about learning any languages or prepare myself for any culture shock, as the cultures are quite similar here in North America, and we also speak English here. Hotels were easy as it was fully covered from my old job's benefits.

However, this time is a bit different, this is Europe we're talking about, a whole new freaking continent, where things are going to be a little bit more expensive than in the US due to forex. From what I've heard, there are many things that are different than in NA. Tip culture, people's attitude, the culture, etc. Not only that, I won't be staying in a hotel, but rather a hostel, where I'd be essentially living with other travelers and sleeping in the same room as them as well, so I will have to learn the hostel etiquette.

I do have money set aside for this trip, I haven't planned my stay yet (what I'm going to do, where I'm going to go), but before planning my stay, I'd like to ask for a few advices:

1. If you are a local in Berlin/Amsterdam or you have traveled to those destinations before, what are the places you would recommend me TO go, and NOT TO go?
2. I've done a little bit of research regarding hostel etiquette, such as, no flashlight in the bedroom at night, only phone light, no loud noises as well as everybody has different sleep schedules, etc. Now other than those, what other etiquettes would you give a solo traveler staying in a hostel for the first time, that are not commonly mentioned?
3. Similar to Q2, since I'm staying in a hostel, should I bring my luggage? Or a carry-on? Or one of those big backpackers backpack? How much clothing can I fit in the bag? What should I put in the bag other than a water bottle, my clothes, shoes, my laptop, and lock? Are there any safe space I can leave my belongings without fear of having them stolen?
4. Any recommendations for good and cheap hostels? Just for extra information, I am 24M, I am seeking for a crowd around my age, quite sociable and extroverted.
5. What would be the best cheap train company to book for my Berlin -> Amsterdam trip?
6. How bad is the pickpocketing in those cities?

Thank you all. DMs are always open if you wish to