An overview about my europe trip and interrail pass.
The nicest way to explore Europe is with the EuroRail Pass which means you are free to explore europe by train. 

It's the opportunity to see amazing places, take thousands of pictures, make friends around the world, learn new words in other language, learn another culture,  try delicious traditional food, create stories to tell,  see things you never did and fall in love with cities!

Later I will do a post for each country where I was.
Check bellow to see how the pass looks like!
When you go to their website to order your pass you will have two options to choose from. 
There's the Global Pass, which allows you to travel all the countries (up to 30) you want to, or the One Country Pass which allows you to explore deeply that big country you've always wanted to visit from north to south, for example: Italy or Norway - in my opinion this pass must be worth it there. There's so much to see, so much to do and so many cities.

5 days within 15 days under 25 years old,
2nd class its 163£ or 200€

We chose 5 days within 15 days because we had 2 weeks holidays and this was the best choice for us. If you are able to travel longer you can choose a pass for up to 1 month.
but what does 5 days within 15 days mean?
It means you can choose any 5 days to travel on within a period of 15 days.
For example, I started using my interrail pass from Amsterdam ➡️ Berlin on the 24th of May. This counted as one travel day, so we still had 4 days left.
We then did:
Berlin, Germany ➡️ Warsaw, Poland
Warsaw, Poland ➡️ Slovakia [here we did a train  change at Czech Republic on our way to Slovakia. Train changes they don't count as a day of travel as long as you started using your day of travel after midnight and finish your travel before midnight next day. So you can in fact visit different countries in one day if you're up for it]
Bratislava, Slovakia ➡️ Budapest, Hungary
Budapest, Hungary ➡️ Zagreb, Croatia
Zagreb, Croatia ➡️ Karlovac, Croatia [again here....because we traveled From Budapest to Zagreb and from Zagreb to Karlovac, all in the same day it counted as just one day of travel]
5 days within 15 was alright for us!

Paris, France  (1 night)
Berlin, Germany (1 night)
Warsaw, Poland (1 night)
Bratislava, Slovakia (1 night)
Budapest, Hungary (3 nights)
Zagreb, Karlovac, Plitvice, Pula, Banjole, Rijeka Croatia (5 nights)

(I've been twice from now in Paris and Amsterdam, so check my old posts for things to do there)

Why did we start using our interrail pass only from Amsterdam?
From London to Paris
The only way to travel between the UK and mainland Europe by train is to take the Eurostar, a private railway company, which unfortunately is not included in the Interrail Pass. Traveling by ferry would be an alternative.
From Paris to Amsterdam
Because we didn't want to use any travel days on our pass yet, we booked our tickets with Eurolines Bus. It's very cheap when booking in advance and it takes 7 hours from Paris. We were in Brussels to pick up more passengers and we had the opportunity to see more or less the city by bus. 

Seats and train reservations:
Some trains requires a seat reservation in advance to avoid disappointment. 
You can book it through their website after you purchase your pass.
I also recommend reading about train travel in each country, using their timetable to plan your trip, check the trains included in your pass and railway stations.
If you are travelling with friends and you bought the passes all separately, your seats might be different. At the empty train coaches you can try to find spare seats for you and your group. When we couldn't find seats for all of us together, we would go to the train's restaurant, order something and just chill there.

How to get in the trains with your pass?
You just have to go to the station, check your train and platform.
Get inside the train and a member of staff will ask you for your ticket.
Show them your Interrail Pass.
Don't forget to fill in your journey details before boarding the train.
"day/month/time" and "from   to   city"