As others have indicated, there are introductory textbooks. They are commonly used in college classes like Introduction to Philosophy. They attempt to do what you are describing. However, there is a high likelihood of there being some errors and oversimplifications, as the person writing the text is almost certainly not an expert on everything. Nor will there be space for giving every interpretation of every aspect of every philosopher's position, so much will be omitted from such a text.
I will give a "classic" example of a book that has been used as an introductory text, and you can do a search for reviews of it, as there are plenty who complain about it, though it also has had plenty of people liking it: Bertrand Russell's A History of Western Philosophy. The Wikipedia article gives some samples of the reactions to it:
https://en.wikipedia.org/wiki/A_History_of_Western_Philosophy
Other introductory texts will have less written about them, because they generally are less famous, but you would have criticisms of them getting things wrong if enough philosophers read them and reviewed them.
However, few are as engagingly written (Russell won a Nobel Prize for literature for good reason). One thing that gets Russell more criticism than many such works is the fact that Russell does not engage in a pretended objectivity; he freely expresses his opinions. I personally like that, as it is more honest than pretending to have no opinion when one does (the author's opinions will affect what is written regardless of them pretending otherwise), and also it tells you who you might want to read about in another book that is more sympathetic to them, to see if they are worth more than Russell suggests.
As for David Hume specifically, the difficulty is primarily a matter of how English has changed since the 1700's. Once one gets used to reading texts of that era, one will find that Hume is an engaging and interesting author. His History of England was a popular standard history of England for about 100 years for good reason. But, if you are not accustomed to reading works of the 1700's, then he is difficult to read, as English has changed since his time.
Also, for specific philosophers, you can look them up in an encyclopedia. For the simplest take on them, you can use a standard encyclopedia, like Wikipedia or The Encyclopedia Britannica or whatever you prefer. If you want more detail and more exactness, you can use an encyclopedia of philosophy, starting with a more basic one and moving on to a more academic one. So, you could read about Hume, for example, at these links, in this order, from simpler to more complex:
https://en.wikipedia.org/wiki/David_Hume
https://iep.utm.edu/hume/
https://plato.stanford.edu/entries/hume/
But if you want an exact knowledge of Hume, you will have to read Hume. So, what one should read depends on what the objectives are that one has, and also what sort of background one has. For some, the Wikipedia article will be as far as they go.
Normally, people start with an introductory text, and later move on to reading the original texts, when they want a more full and more exact knowledge of what the philosopher had to say. Though one might read selected passages of David Hume's An Enquiry Concerning Human Understanding in an Introduction to Philosophy class, I doubt that very many such classes have the student read that entire book. A more advanced History of Western Philosophy class, however, may have the student read it, as it is a very significant work of philosophy and Hume has been extremely influential. (And as an aside, An Enquiry Concerning Human Understanding is itself a mostly simplified version of Book I of Hume's A Treatise of Human Nature, though there are also some differences in content.)
So, if you are just starting out, using a textbook may be the best beginning. However, you should keep in mind the limitations of such a beginning, that some philosophers and some ideas may not be properly represented.
Philosophy is different from other subjects like Biology (to use your example), because the methods used in biology are more agreed upon by biologists than the methods of philosophy, about which different philosophers disagree. How to engage with the subject is disputed among philosophers, whereas biologists have a greater agreement about what the right way is to go about studying biology. This makes it easier to write an introductory book about biology that will be acceptable to most biologists than it is to write an introductory book about philosophy that will be acceptable to most philosophers.