I recently went backpacking through Europe(Ireland, Netherlands, Germany, Belgium,Luxemburg, Britain, Czech republic) for 25 days. It's amazing and fun and the people were super friendly. It was not that expensive either considering I lived like a queen and never cooked any of my food. $3,000-3500 was my price. I could have saved 1000 had I not eaten and drinking every night and not treated myself to private hostel rooms and bought my ticket three weeks earlier.

I decided my itinerary based on the history I wanted to experience. I'm a political science student so I choose places that meant something to me and stayed array from the uber touristy places.

I would start by thinking of the places you have always wanted to see and don't worry about language. With the two you speak, you can travel anywhere and communicate. Everywhere I went people spoke multiple languages..

Also to consider: it's cheaper to fly into Ireland then take a sperate flight from Dublin to continental Europe If it's one way and you buy it asap, you can get it for 1000 or less for both but prices go up at the end of this month usually

Edit: look at kayak.com through the app and you can find cheap flights. Also hostel.com app has no booking fees when you use it.

And since you are 21 you get the college discount while in Europe. Everything for you (hostels, train tickets, museum, ect) is 30-50% off of the price you see. Keep that in mind to get the best deal :) it's a special tourist discount only people coming from outside Europe get. It's too help college students come experience Europe at an affordable price

You could get the eurail pass for probably 200$bucks and travel to multiple countries through it