Croatia itinerary help - no car

We did not have a car in Croatia and traveled by bus and ferry and both were scenic and easy. We took the bus from Split to Dubrovnik. Didn’t go to the lakes or Zagreb so can’t answer to that. You might want a bit more time in Split than what you have so far. At least a full day minimum.

I go to www.BusBud.com to see the bus schedules and buy online tickets for the many bus companies on one website. Another website is www.GetByBus.com. When you arrive at Dubrovnik’s Airport (DBV) the bus will pick you up from the curb right outside the terminal exit doors. The buses are timed to meet arriving flights ( that’s how small the airport is) You can buy your ticket online on BusBud for about $10. Try to sit on the driver’s side (left side) of the bus because you’ll be able to take photos of the spectacular coastline and Old Dubrovnik from high above. Dubrovnik to Split is least expensive by bus. You can take ferries as well, but that is a better option if you’re spending some time on the offshore islands such as Korcula and Hvar. www.DirectFerries.com shows schedules and pricing for ferries not only in Croatia but worldwide.

If using public transit, getting from Split to Plitvice Lakes has to be by bus and it takes anywhere from 3.5-6 hours depending on the bus company you go with. There’s a 7am bus arriving at 10:30am at Plitvice Lakes for about €22. If you take this bus you will only need one night at Plitvice Lakes because you will have the entire afternoon to visit the lakes. Split’s main bus station ( “Autobusni Kolodvor Split”) is on the harbor near the ferry dock.
I think you might want to rethink flying to Budapest from Zagreb because there are about four direct buses most days taking just 4.5 hours for about €29 to make that journey and you won’t need to deal with airport hassles or transportation getting to and from the airports. There are no direct flights from Zagreb to Budapest and flights begin at about $100 one-way. If you still want to fly, www.Skyscanner.com has ticket prices and schedules.
You might want to go to Lokrum Island on the day after you arrive in Dubrovnik. It’s a National Park, has great beaches, a fort Napolean built from where you can see Old Dubrovnik and a historic monastery that has the Iron throne from the Game of Thrones on display. A 15-minute boat gets you to Lokrum island.
You can add a night to Zagreb by taking the early 7:00 am bus to Plitvice Lakes and staying one night there, and you also can add one night to Split by taking a morning bus from Dubrovnik to Split and arriving before noon. Split is worth at least 2 nights.
Have a great Trip!

We did a similar itinerary this past May.

I agree with staying overnight at Plitvice. If you stay at one of the park hotels, you can go into the lakes twice, included in your stay. So, you can go during the less busy times: in the late afternoon, after you check in, and you can go early in the morning before checkout and before you go to Zagreb. That is what we did, and we thought it worked out brilliantly.

We used Octopus Transfers to go from Split to Zadar, Zadar to Plitvice, and Plitvice to Zagreb. It wasn't the cheapest option, but we were able to travel at times that worked for us. https://www.octopustransferscroatia.com If you can afford it, you might want to consider this, since you have such a short time in Croatia.

We spent three nights in Hvar, so we took the ferry from Dubrovnik to Hvar and then from Hvar to Split. So, I can't comment on how convenient taking the ferry to Split might be. I do know that ferry times from Dubrovnik to Hvar were limited at the time of year we were there, with our only option being an evening ferry. https://www.jadrolinija.hr/en/about-us/ships/ferries

Thank you so much for the detailed information. I will look into them and come back with any additional questions.
This helps re think a few things :)

Just went through the planning stages myself, here’s a couple things I found: Jadrolinija is the only ferry line running north and departs at 7am. Bus might be more convenient, but I’d certainly learn towards the ferry for some views (you’ll stop at Korcula and Hvar on the way.) There seems to be a fair amount of busses via getbybus.com connecting Plitvice and on to Zagreb. The site works well, and the ticket comes with detailed pickup/drop off info. I feel confident about it.

Check-in time at Plitvice hotels is kind of late (2pm) and trying to line up your arrival may be tricky. Though you can check bags there or at the park entrance. The entry ticket for the park only guarantees entry within the hour you select, so be sure that lines up comfortably with your arrival. This one night in Plitvice felt complex to plan.

Krilo also runs catamarans. I'd probably just go with bus if not stopping on an island.
https://www.krilo.hr/wp-content/uploads/2018/11/Sailing_schedule_DUBROVNIK.pdf
https://www.jadrolinija.hr/docs/default-source/o-nama/dubrovnik---kor%C4%8Dula---hvar---bol---split.pdf?sfvrsn=7097412b_1

I would be less worried about the bus being full when heading toward Zagreb, but I would try for an earlier bus and not wait for the last one of the day for sure.

Thanks for the updated info on Plitvice - I was having issues finding a bus on 5/29 - both the sites above wouldn't list the 5/29 date but I was able to get a ticket via the Rome to Rio bus site - weird huh?
I have lodging booked and asked them about getting there in time and they mentioned taking a taxi to the B &B - I took the 7:00 am bus just so I have more time and have booked a 2 day ticket for the Lakes starting at noon - I wasn't aware of the only 1 hour grace period so hopefully taxi to drop off luggage and then to the entrance witihin the time frame will work (fingers crossed),