I'm not sure about the budgetary constraints but when I was there we stayed in cavtat the first night, seemed like a nice enough little semi-contained resort town with decent swimming and some restaurants, and a lot of fancy yachts. dubrovnik definitely worth a visit though eating within the walls can be expensive. split was great - good fun watching people play picigin on plitvice beach at sundown. we day tripped to mostar (in bosnia-h) from dubrovnik too which was worth doing.
we never made it to any of the islands or national parks... though hear they're the true stars of the show
― ... and the crowd said DESELECT THEM (||||||||), Saturday, 13 April 2019 09:55 (five months ago) link
June may still be early enough that the national parks aren't mad busy, but idk - wouldn't bet against it either
Zadar and surrounding region are very user-friendly, particularly for public transport - the buses (and app) are excellent, even extending out to buses on the islands (Ugljan and Pasman)
― cherry blossom, Saturday, 13 April 2019 10:03 (five months ago) link