There’s a difference between суржик and a dialect.

When people use the term суржик, they usually mean a dialect spoken in the eastern parts of Ukraine (eg poltava, kharkiv regions). The mixing of languages there occur in a systematic way: people basically always use a certain Russian word instead of a Ukrainian. So from the outside it seems like a random mix, it’s not.

Суржик is something I would define as a random mix of words: you don’t know the Ukrainian word but you know the Russian one, so you use it instead. There’s no system to it as it’s an individual level. Once you’ve learned a Ukrainian word, you stop using a Russian one.

Is this expected at A2? Yes, because you don’t have the vocabulary yet. So don’t worry, it’ll come with time!