How many Russian words do you need in daily life?
Vocabulary do not say anything about how well you can construct a sentence, but it is of course essential if you want to understand what people say. You can also make yourself understood, even if you put the words together in the wrong way. Contexts can make up for bad grammar!
So how do many Russian words do you need to know to use a language? It is a fact that native speakers know 15,000 to 20,000 word families. This means that a word such as впечатление (impression) counts as one word no matter how many ways you can change its endings. It’s only one word family.
Learning 20,000 of such word families sound exhausting! However, the relevant question is how many Russian words are actually used in daily life?
My realisation came when I was doing an internship in Kiev. For most things outside of work that need to done daily, I never used more than 100 word families. Ordering food, saying hello and asking polite questions, setting up a meeting. I did not have Russian classes during this period and I found that my Russian as a whole actually got worse. Yet, I could speak basic Russian much faster and without thinking. So the vocabulary you need to survive is very limited.
Similarly, I came back from my first summer course at Lidenz last year with about 2,500 word families according to my learning app. This is nowhere near 20,000, but I rarely ever faced problems communicating in person. It is only when you discuss complicated topics, read books or watch films that it becomes hard.
I can go on with examples of each step, but the point is clear. For simple purposes, you can get by with surprisingly small amount of words. For other purposes, it will increase, but research shows that you do not need anywhere near the 20,000 mark that native speakers have to be able to converse at almost-native level. Pass a certain point, you can guess based on context what a certain word you do know means.
So even when you are at A1/A2, look up the 100 or so most common words as phrases in a language and learn them. You’ll get very far. No need to wait to get to a certain level.