I would like to know how many people are in my family tree
Because FamilySearch tree is a universal tree for all, there is no way for them to give you the perspective and numbers you seek. All families are connected in this tree and you can't tell where yours ends and another begins. For information like that it is best to use a software program on your computer, those allow you to see that information.
If you sign into FamilySearch and go to Family Tree. Along the top menu you will see My Contributions.
Click on My Contributions and the Menu tab at the top will show statistics.
See the article from the Help Centre below for more information:
I hope your question has been understood and helps provide an answer.
I wish you well with finding your ancestors.
I am just a 'lowly' User/Patron ...
Short Answer: 'No', unfortunately not, in regard to how many People are in one's "Ancestral" Lines.
Well, the answer would not be reliable. Sometimes I have had lines go to a dead end, where I know there are known ancestors somewhere. Doing a search on the "dead end" can bring up potential parents to evaluate based on a variety of sources OR based on a search of the existing tree. Twice I have found the "other half" of an ancestor of mine who came to America, appearing from seemingly no where other than vague references to a country. Eventually I found another record where someone of the same name, same birth date and a specific place in said country who was born into a known family, raised, and then vanished into thin air. In both cases, after consulting with content contributors in those other records, we agreed merges were the way to go. All of a sudden my dead ends went back lots more generations.
In a presentation by Ron Tanner in 2019, he stated that the largest single tree in Family Tree had 498,980,000 individuals. In 2020, over 100 million people were added to Family Tree. I haven't seen any posting regarding 2021 yet but would assume was about the same if not more. Since most of them are going to be added to that interconnected tree, you could probably assume that single tree is now about 800,000,000. If you have ever clicked on View My Relationship and found that you were a person's 10th cousin, or more remote, then you are certain to hook into that main tree in Family Tree and can assume that there are pretty close to a billion people in your tree.