Hi Helene and welcome to the forum,
A few points there I will cover for you
I think having your own website should most definitely be the ultimate goal, but you have to crawl before you can run and it's that that easy to create your own successful website straight away. So yes, I think eBay would be a solid place to start, Now I notice that you are making a rookie mistake straight away in wanting to know the top selling items on eBay.
Dropshipping offers some benefits, but a competitive price isn't one of them. When you are selling in the top markets on eBay, then you are competing against some BIG sellers and big sellers have BIG resources. So you can be up against sellers buying in super large wholesale volume, ensuring they are getting the best possible purchase price, and then they are selling on a very tight margin and relying on turnover for profit.
So straight away, as a dropshipper you are going to be seriously out gunned and find it next to impossible to compete.
I see a lot of rookies who start off dropshipping make the mistake of thinking they are competing against other dropshippers. Well, truth be told, yes, they are, but other dropshippers aren't the biggest threat. They are the big time wholesale sellers with all the resources behind them and a dropshipping just can't run with them 99% of the time, certainly not on a product to product basis.
For dropshipping on eBay, we always suggest the smaller markets, Markets where sales are much slower, so not a high turnover in sales, but those markets typically aren't saturated with big cashed up sellers, so it's more of a dropship marketplace and one that gives dropshippers a decent chance.
In regards to what suppliers you can use on eBay, you can use any dropship supplier to sell on eBay. What you need to focus on is where you can actually sell to, and that is only limited by where your supplier's ships to. If they ship world wide, then you can sell world wide and so on, you don't have to limit yourself to Norway alone.