Where and how did you look?
Your immediate ancestors, born since 1930, may not be on this site or any other, because of privacy laws, and the fact the databases may not have been released.
If you can find a grandparent in the 1930 census, it is not too difficult to trace them back to the 1850 census, or find your ancestors born in the first quarter of the 1800's.
Then you work really starts, as you prove the relationships. There are many places you can find advice on the "how" of additional research.
What ever you don't merge families from other online trees, as many are not worth the space on the internet they occupy.
Do use the online trees for research ideas, and make use of any reference material you may find.
If you borrow, don't forget to thank the person who owns the tree.
Don't be afraid to contact the individual. The exchange of ideas will help you both. You because it is new information; them the chance to rethink the information in their database.
Remember you are learning about your family, not passing judgement on your ancestors. Once you find them you may find they have done things that you approve of, but they are your ancestors and they became you.
Don't forget, it is fun. It like playing the game "Clue"