First, let me discuss the issue of identity. Suppose your grandpa owns an antique pocket watch that he has willed to you. Suppose he keeps it in a safety deposit box in a bank. Suppose he also periodically takes you in to the bank to look at the watch, so you get to know the appearance very well. Now finally suppose that your grandpa, alas, dies and two untoward things happen in the bank. First, a clerk accidentaly drops Grandpa's watch and it receives a long scratch across the back and second, when you come in to pick up your bequest, the bank manager makes a mistake and hands you a different watch, a watch belonging to a man called Smith that just happens to exactly resemble Grandpa's watch in every respect, and so you take it to be Grandpa's watch, and for the rest of your life you carry this watch around in the happy belief that this is the watch your grandpa owned, even though it actually is not the same watch. Meanwhile, Smith collects the other watch, and, not minding the scratch, takes away Grandpa's watch in the belief it is his own.
So there's two watches. There's the watch that Smith now holds, which is actually the same watch your grandpa used to own, even though it is different, owing to the scratch. And there's the watch you now hold, which is not the same watch your grandpa used to own, even though it is physically the same in every respect.
When the Ship of Theseus problem asks, if some ship is the same ship as the ship Theseus used to sail, it is asking if it is that ship in the sense that the watch held by Smith, with the scratch, is the same watch that your grandpa used to own. It is not asking if it looks the same, feels the same, sounds the same or smells the same, it is asking if it is the same ship.
Now read one or more of the following articles:
The Ship of Theseus
The Ship of Theseus and Personal Identity
Identity, Persistence, and the Ship of Theseus
The Ship of Theseus and the Question of IdentityVideo
When you think you have a good understanding of the issues involved in the Ship of Theseus problem, take some more "think" time do your best to come up with the most logically justifiable answer you can think of. When you have thought about the issue, write a paper explaining the problem, explaining what you think about the problem, and saying exactly why you think what you think.