Welcome to the world of genealogy. One of the very first things to learn about is documentation, and second to never assume another tree is accurate. As you will learn as you progress, there are many, many inaccurate trees both here and on other sites.
There are many experienced researchers here that will gladly help you along the way, so ask questions if you need to.
I looked at your tree, and it looks like you got a number of ancestors from other trees. If you can prove all these by documentation (census, marriage license, birth or death certificates, obituaries, etc.) that's great. But if you can't, I would suggest you delete those ancestors as there is at least a 50% chance they are wrong. It's very tempting to gain all these ancestors by just assuming others are right, but it is very wrong.
Start with your known ancestors... parents, grandparents, and fill in what you know (and can prove) about them. At that point build back to the next generation by using the records here on ancestry as well as informaton from other sites as familysearch.org.
The leaf hints that will show on your entries are just that... hints. It is up to you to prove they are your folks.
Other ancestry trees, in my opinion, are good for one thing, and that is "possibles". If I get stuck on someone, I will look at someone's tree to see what they believe is right. Then I research to see if I can prove that relationship... if I can't prove it, I won't add it.
You want to have an accurate tree, and one you can be proud of, but it takes a lot of work to do so -- true ancestors are not just a click away as is sometimes inferred on some tv advertisements. I'd be more than willing to give any help possible, just email me at
lindad612@hotmail.com, and I'll gladly help. I've been researching my families for 30 years, and enjoy helping new researchers.
Linda