You earn €30k gross.
You owe €13k + €2.5k + €1k = €16.5k more than half your gross income and by the fact that it is not a mortgage and you are looking to buy a car it is hard to see what you have for your debt.
I am not saying you are living beyond your means but I do think you need to look carefully at your spending habits in general!
Two short term aims:
You want to do a course in February (next month) which will cost €2k - which I am going to guess you don't have tucked away anywhere. How are you planning to pay for it? Are you intending taking another loan to cover it?
It will cost probably at least €1.5k to travel to Australia (excluding spending money while there btw - including that I would up that to over €2k - despite the accommodation on offer, I doubt you plan to stay in every night, only visit free attractions, drink water and walk everywhere while there

)
One medium term aim:
Buy a car - you have given no timeline or budget on this.
One long term aim:
Buy a house ~€200k, for which you will need a minimum of a €20k deposit plus money with which to furnish it probably.
Honestly if I was you (and willing to carry the debt you seem to be comfortable with) I would pick between either the course or the holiday and postpone the other for a year. I would plump for the holiday as you are unlikely to manage to save enough money in time to pay for the course and may not be able to access the finance to pay for it.
You have a lifestyle spend issue - your income is stretched (as evidenced by your credit card maxed out and your overdraft at €1k - think about it, between the two of them that is more than 10% of your GROSS income!). I am going to be generous and guess that that is partially a hang over from Christmas and not a constant habit.
I'd agree with webtax - whatever you decide - now is the time to tighten your belt and learn to achieve your aims by paying forward for them rather than back.
1) Draw up a budget - and be honest if you want to save 400pm, write out all your outgoings, don't forget to provide for expenses that occur at a longer interval than the interval you budget for (so if you budget for a week, divide monthly expenses over the weeks in the month). And don't forget to budget for things like presents for family and the unexpected (doctors 'n' dentists cost)
2) Stick to it.
Tell your friends that you are planning a big holiday so you can't head out on the town
Shop smart - turn up with a list, only list what you need, stick to it, compare prices, check out the cheaper discount shops.
Keep all your receipts - and use them to tally your costs - keep a spending diary.
3) REDUCE your credit card debt and tackle your overdraft. These are very expensive debts. They cost you a fortune every month and even worse over time. Besides - if you do head down under you want to be confident that you can use your card - you get the best exchange rate and it is very useful in emergencies.
On the other two aims...
In terms of saving for a house, if you were to redirect your putative €400pm into saving for a deposit it will take you 50 months to save it. That is just over 4 years. A 25 year mortgage for €180k will probably cost you around €1k per month - which is more than the sum of your proposed savings and your rent. In order to get a mortgage you would also not get anywhere if you have the debt load that you currently carry.
In terms of buying a car - always remember a loan on a car is doubly expensive as you are paying interest on a depreciating asset - you can never recover the cost of your original investment if you try to sell the car. It is better if you can buy it with your own money - for €10k it will take you two years to save that. Then you have the cost of running the car on top of that.
What I am trying to say is that while €400pm is a good start assuming you can actually manage that - if you are planning to save for a house and a car you would need to be saving much more. Which goes back to my original point - you need to seriously reconsider the cost of your lifestyle, you have hard choices to make.