Hoo Boy.
First off, welcome. It's a really fun sport filled with some very amazing people.
Second, don't focus only on a 'ultimate goal of wingsuiting'. Focus on becoming the best, most skilled & safest jumper you can be. The rest will follow. Enjoy the journey. You may find other disciplines to be something you want to do. Either as a side road on your journey to a wingsuit, or as a completely different path. Unitl you've done it, you have no clue what it's like. Formation work (belly), freeflying, canopy flight, instruction, rigging, even flying the planes. Each part of the sport has things that are very attractive to some folks.
"Best" and "Cheapest" don't go together. Ever. I would look for a DZ close to you that has a track record of creating licensed jumpers from the students that start. One question I would ask is: 'How many students did you have that got their license last year?' Or maybe in the last few years because 2020 was so screwy.
Keep in mind that AFF or IAD are instruction methods. Once you get to 'solo student' status, there's still a ways to go to your license, and that's where the real adventure (and learning) begin.
How much? That depends. I know Europe tends to be more expensive than the US. I've said more than once that, no matter the training method, you can plan on somewhere around $10k (USD) to get your first license and all the gear you need. It can be done for less, but it takes a fair amount of skill, patience & luck.
For the rest of the jumps, it will not be cheap. Here in the US, I usually pay $20-$25(USD) per jump. Getting to the minimum 200 (next 175 after the initial 25 for the license) for a wingsuit will cost $4k-$5k.
And that's a minimum. Not everyone is ready to get into a suit at that point.
How long? Again, it depends. How much can you afford to jump? The weather where you are isn't always the best, can you go somewhere like Spain? There are a couple good DZs there, they tend to have better weather and attract jumpers from all over Europe (and the US).
Again, 2020 has been really awful for lots of this sorts of thing. Hopefully next year will be better.
If you are 'studying', are you a college student?
I would suggest finding something you like that pays well. It's a lot better to have a lucrative job, and jump as a hobby than to try to make a living at it.
I would take at least a couple meteorology courses. Weather is a huge factor in this sport. Being able to understand and predict it is very helpful.