Welcome! Mistakes are just feedback on your way to fluent English. Let's practice together!
Present Simple vs. Continuous: Routine (I play) vs. Now (I am playing)
Past Simple vs. Continuous: Finished action (I walked) vs. Action in progress (I was walking)
Present Perfect: Life experience / Result (I have seen)
Future (Going to vs. Will): Planned future (I'm going to travel) vs. Sudden decision/Prediction (I'll help you)