If i may give one (1) tip to A0-A2 learners of Slavic Languages:
Study both verb aspect forms from the get-go.
Slavic languages have a grammatical category called 'verbal aspect' which, simply put, expresses either that you are/were/will be in the process of doing something (imperfective aspect) or that you have or will have gotten a certain result (perfective aspect).
What do I mean by 'study them from the get-go':
Personally I use Anki (beloved) for vocabulary study, but I guess you can apply this to whatever suits you best.
Russian example sentence in the text book: "Вчера я купил яблка." [Včerá ja kupíl jáblka. Yesterday I bought apples.]
In the vocab list* I find the infinitive of купил [kupíl; bought]: купить [kupít'; to buy].
I head over to wiktionary and type in the search bar the infinitive form and hit enter. You should now see something like this:
What we're looking for is the 'Verb' section, and, specifically, that first line of the paragraph that mentions the infinitive, an abbreviation for its aspect [ipf. = imperfective, pf. = perfective] and, in brackets, the 'opposite' verbal aspect. In this example, we learn that купить has the perfective aspect, and its imperfective equivalent is покупать [pokupát'].
This is how I structure my Anki card then:
(german is my mother tongue so it's russian - german - spanish. the latter is there just as a reminder for myself, please ignore lol)
I always put the imperfective form on the left - then slash - then perfective form. I highly recommend to maintain a consistent order.
So, our textbook example mentioned only one form. That is the one I am going to be studying actively. Meaning: When the card 'to buy' pops up, I try to remember only the word that came up in class/read in the textbook etc., in this case купить. I turn the card and check if I got it right, then read both forms (optional, but helpful: read them aloud).
What this does is that it familiarises you with both aspect forms without putting the pressure of learning twice as much vocabulary on you.
You will have to learn both aspects at some point, but it will be so much easier when you're already actively familiar with one form and passively familiar with the other. I started doing this during my second semester and it was SO WORTH IT.
Let me know if you have any questions or if this was helpful to you! <3
*in absence of a vocab list, I use this website for Russian and this website for Czech. you can type the exact verb form as you encounter it (in this example купил) and it will show you the entire conjugation table. extremely useful to have at hand