As you are new, it’s worth pointing out that the player is not the one who calls out “I want to make a Nature check”, for example. Instead, the player describes what the PC wants to accomplish: “I want to see if I can identify the strange plant”. And then the player describes how the PC plans to accomplish it: “I pluck a leaf and inspect it closely, referring to my botany journal”. The DM then let’s you know if you succeeded (“yeah, you grew up with one of these in the woods behind your house”), if you failed (“this is some alien plant that no one has likely ever seen in this part of the world”), or if there is some uncertainty (“please roll a Nature check to see what you know... and to see if you are poisoned or not!”).