Speaking like this is slang, and used in colloquial English.
Examples of "get/got" depend on present or past tense.
"I get it." / "I get you" is present tense.
"I got it." / "I got you" is past tense, but people often say it while referring to present tense.
We don't exactly use "catch" you. But instead we could say something like:
"I catch your drift." - present tense. It means "I understand what you're saying"
"I caught what was going on" - past tense. It means "I understand what happened"