Can you rent a car and drop it off in Copenhagen? 

We're actually going for the world cup qualifier between Ireland and Denmark. I hear drinks are very expensive there.  but I also hear drinking on the street is allowed.  I've a feeling half of the Irish travelling will be buying cans and drinking on the street xD

So I was looking at train tickets.  €37 if you are 25 or under.  €50 if you are over 25. Are they strick on that?  My friend is 25 now but will be 26 by then.  My other friend is just gone 26. Would we get away with the cheaper tickets? 

And accommodation in Copenhagen is meant to be very expensive.  Any tips?  Preferably would like to not pay more then €100 per room per night.. 

You can always rent a car in one place and drop it somewhere else, it just costs more money.
I would have thought you had the return flight at Billund, so you could use the rental as a means to get back.
Just check how much it costs, it might be cheaper than the train if you are a group.

For accommodation maybe look around the outskirts,
somewhere that is nicely connected via the train so you can easily get to the city.

Copenhagen has a bunch of nightlife activitites. You can read about some of them here. Accomodation in Copenhagen is really expensive. The hotels are really good but if you're travelling on a tight budget I'd suggest checking out Airbnb or hostels.com. Cheapest way to travel from Billund to Copenhagen would be by bus or train. Just ask for help in the airport. People are really nice.
Bus from Billund to Vejle ~ 7€
Bus from Vejle to Copenhagen ~ 17€ (book well in advance on flixbus.dk)
Train from Vejle to Copenhagen ~ 12€ (book well in advance on dsb.dk, only "orange tickets" (tickets that are booked early) are that cheap)

I'm from Denmark. Grew up in Randboeldal (Randboel Valley) approx. 10 km from Billund. The nature is pretty great in this area (forest valleys and lakes) combined with historical Viking landmarks (Rune Stones, Viking ships, etc). If you visit places even closer to the sea in Eastern Jutland, the nature will be great as well.

I suppose you already know about attractions in Billund like:

Legoland

Lego House

Lalandia

Be careful with the youth tickets, I think you need to buy a specific youth card, that you need to show in addition to the youth ticket for it to be valid.

If you are fast and lucky you might be able to buy the cheaper Orange tickets, but be aware, they have to be used on that specific train they are bought for, and they can’t be refunded. If you don’t buy an Orange ticket, then just wait until when you are there to buy tickets, since the prices for regular tickets won’t change.

Thanks for the tips. Denmark loks pretty :) 

BTW i can't seem to find any "Orange" tickets

It's the nickname of the Danish football team. It originated around the time that they won Euro 1992, but they haven't exactly been dynamite since then, so it's probably not common knowledge anymore.

My post was a joke on the panic/outrage that can be caused by mentioning words like 'bomb' in an airport.

It's the nickname of the Danish football team. It originated around the time that they won Euro 1992, but they haven't exactly been dynamite since then, so it's probably not common knowledge anymore.

My post was a joke on the panic/outrage that can be caused by mentioning words like 'bomb' in an airport.

Ka-pi96 said: Enjoy the footie! Hope you Irish win

It's true that we like beer. Lately, we've fallen a bit behind though. Going from 10th among OECD countries in 2013 to 20th in 2015.

List of OECD countries by the total alcohol consumption per capita in litres of pure alcohol in 2015:

Rank	Country	Alcohol consumption in litres
1	Czech Republic	14.1
2	Australia	12.6
3	Portugal	12.5
4	Slovakia	12.5
5	Hungary	12.4
6	United Kingdom	12.0
7	Finland	11.9
8	France	11.6
9	Poland	11.5
10	Luxembourg	11.2
11	New Zealand	11.2
12	Ireland	10.9
13	Slovenia	10.9
14	South Korea	10.9
15	Belgium	10.8
16	Germany	10.6
17	Spain	10.6
18	Switzerland	10.4
19	Canada	10.3
20	Denmark	10.2
21	Netherlands	9.6
22	Chile	9.3
23	Greece	9.3
24	United States	9.0
25	Sweden	8.7
26	Austria	8.5
27	Japan	7.5
28	Norway	7.0
29	Iceland	6.9
30	Mexico	6.8
31	Italy	6.1
32	Israel	3.1
33	Turkey	2.4

My experience is from 7 years ago though.

No problem

You gotta tick the "Show me Orange tickets" before you click on "Search journey".

Here are some of the "orange" departures from Vejle to Copenhagen on October 11:
12.57 - 15.05 for 92 kr. (12.36€)
13.56 - 16.05 for 101 kr. (13.57€)
16.04 - 18.57 for 101 kr. (13.57€)
18.04 - 20.57 for 92 kr. (12.36€)

Alternatively, you can rent a car which may be cheaper if you're a group like TomaTito said. But be sure to rent it from your home country as that'll save you a lot of money. A couple years ago I rented a car in Australia and later discovered that I could've saved 200+ € if I had done so through a Danish unit in the same car rental company

If you end up follow this through, enjoy the match (maybe I'll join you). And when you're in Copenhagen remember to visit Mikkeller Bar and taste the beer awarded one of the 3 best in the world.