Pitivice lakes from Spilt

I do not recommend day tripping to Plitvice from Split (or from Zagreb). This subject comes up rather often here. If you scroll back through the Croatia forum, you'll find quite a few threads about itineraries where the topic is discussed.

During peak season and even during shoulder season, the park is totally mobbed by day trippers. The result is that the walkways (which mostly are without guardrails) are shoulder-to-shoulder. It really turns the experience from something magical into the mundane, or worse. If you take a tour from Split, you'll be part of that mob. The only way to really enjoy Plitvice these days is to spend a night in or near the park so you can see it either late on your arrival day and/or very early the next morning. Believe me, I know--I day tripped in from Zagreb in 2015, and it was a very disappointing experience.

An option as a day trip from Split would be to go to Krka. https://www.npkrka.hr/en_US/