Hi Carlos and welcome to the forum
It is exciting just starting out, but can be confusing. In regards to getting an eBay store straight away, it's not something I would personally recommend, it's just an added expense for anyone just starting out and when dropshipping, you really need to focus on keeping the costs down to an absolute minimum. So my advise would be to use the standard eBay listing format.
In regards to what to do next, it's far to simple to say that you just have to jump into the directory, find a dropshipper and start selling. You're entering a very competitive market, and I mean VERY COMPETITIVE MARKET!
The biggest mistake anyone makes in this business is underestimating just how competitive it is, they get frustrated and then give up before they even get a chance to really start. I'm not trying to pour cold water on you lol, but just trying to temper your excitement with a little dose of market reality lol
Imagine this, you go and set up a stall at a weekend market selling product X.You get the stall all set up and then look around and see that you are right next to another stall selling the exact same thing, then the next, then the next, then the next........ as far as the eye can see, everyone selling the exact same thing as you and all the customers are walking past everyone's stall choosing who to buy from.
Would you pay money to have a stall there in that market?
Well when you sell on eBay, that's the type of scenario that you are faced with and that should give you an idea of just how high that mountain can be to climb. It's not a quick sprint to the top in this business, especially with dropshipping, it's a seriously long winding journey full off steep drop offs that are around every corner.
If you've gone through some old posts, the one thing that may be starting to stick out is the word research. It doesn't matter how long you've been in this business, just starting or a 25 year veteran, research is what it's all about. The minute you lose sight of that, is the time your competitors will take the advantage and you're dead in the water!
Selling some stuff from around the house is a great idea to get started, but now you are looking at selling the exact same products, in the exact same place, through the exact same supply method, then thousands are doing from all over the world ......... market stalls all the same, as far as the eye can see.......
You need to know your market before you even think of finding a supplier. You need to identify product, competitors, price points, suppliers and so on. Even after that, you then need to work out how to make you stand out from all the other stalls and with dropshipping being so competitive, price usually isn't an option. So you have to start working on building a brand, create an online environment where customers feel comfortable spending their money and so on and that's often one of the hardest parts of all.
Use that excitement to shoot yourself into the research and get started, just temper it with reality and try not to move too quickly before you ahve all the building blocks in place to give yourself the best possible chance and anytime you need any help, just shout out, that's what we're here for :)