Learning to read Latin, or any other language for that matter, in an exercise in vocabulary acquisition, and you can't escape this.
Many, many years ago, when I was at school we were given lists of Latin (and French) words to learn in the evening. We were then were tested on them the following day.
I always failed these tests, and left school having retained no Latin or French, and with the conviction that I couldn't learn languages.
But having digressed, with that unhappy anecdote, lets now return to my theme reading Latin and learning vocabulary.
In essence, there are two types of vocabulary, higher frequency words which occur constantly in any text, and low frequency words which occur rather less frequently, along a sliding scale of frequency.
The higher frequency words will occur in virtually anything that you read. Already in writing these few sentences, I've used words such as 'many, I, was, were, we, read, then' and so on, all words that you have to know to understand English.
Lower frequency words are often domain specific. For example, as a mechanic, I might use words like 'spark plug', 'rev counter' or 'torque wrench'.
You could read hundreds of books (or watch a lot of television and other media) and never come across these.
So you may wonder how this relates to Latin and Winnie the Pooh?
I am no expert on Latin, but the literature (and varieties of Latin) can be split into periods such as Classical Latin, Vulgar Latin, Medieval Latin, Renaissance Latin and Church Latin.
The periods or varieties will naturally encompass different vocabulary (the low frequency words), and also include many common words (the high frequency vocabulary).
Regardless as to the period that you are reading, you need to understand the high frequency words, and a good way to do this is through books like Winnie Ille Pu, or Harrius Potter.
These are particularly good because they both contain high frequency words, and they are translations of books written in English, which you can read them in English first - if you haven't already.
When you read a lot, the high frequency words occur ... frequently, and almost by osmosis you learn them. Admittedly there are other methods of vocabulary acquisition such as Anki, a spaced repitition system, which is extremely popular.
Personally, I've never been organised enough to use these systems successfully, but I can always find time to read. I'm also not particularly keen on word lists, especially in languages such as Latin, as I prefer to see how a word is used in a sentence. This is particulary important in an inflected language such as Latin.
I'm a strong advocate of reading in general and one of the reasons that I learn languages is that I like to read.
For example, I can more or less read French although I can't speak a word. I've read one of the very first 'Locked room' mysteries in French The Mystery of the Yellow Room, or Le Mystère de la Chambre Jaune.
I didn't understand every word, but I read it on a Kindle with a French dictionary which helped. I'm pretty sure I'll never forget the word chambre again.
I mentioned the Kindle, in case I'm coming across as a total luddite. Personally, I think that physical books for learning languages are preferable, as sometimes it helps to underline or write words in the margin.
Reading helps increase vocabulary, but is not often associated with learning Latin (at least in the early stages), and for those of us (of whom I am one) who don't feel up to launching into the various classics, there is a still lot of light reading;)
Don't look every word up that you don't know or you will soon give up. Equally don't worry if you don't know every word.
Focus on looking up the high frequency words.
As for me personally, I like, especially in the winter to dabble with Latin, and I also to read (or decipher!) inscriptions whenever I see them.
Even if that means taking a picture, and looking up the unknown words when I return home.