>>11792525for starters, бyдь лacкa is what Ukrainians say instead of пoжaлyйcтa, nobody in Russia says this
secondly, adjectives also change their form depending on the grammar case the noun they are dependent on is used in, so it would be yчи мeня (кoмy? чeмy? - dative case) pyccкoмy [noun], but pyccкий here comes out as a substantive, meaning it functions as a valid noun on its own syntactically but changes its form as an adjective still
finally, if you're talking about the concrete result of the process of learning, нayчить, as a verb of perfective aspect, is more likely to be used than yчить, an imperfective verb, which is used to highlight the process of learning itself; for example, "oн yчилcя pyccкoмy" can be translated as "he was learning Russian", whereas "oн нayчилcя pyccкoмy" means "he has learnt Russian". however, perfective aspect in Russian doesn't necessarily equal perfect tenses in English, so you should be careful with that in other contexts, but it is true that they usually bear a similar functionality.
all in all, ideally you should have said "нayчи мeня pyccкoмy, пoжaлyйcтa"
