Triglav (2864m) is not only the tallest mountain but is debatably the most iconic peak in Slovenia. It is a sought after summit by both locals and international travelers. Additionally, the Prag Route (north face) is a beautiful nearly 1000m face and is both steep and challenging. Many people try to complete the climb in a day, up (and/or) down, or stay at one of the many huts in the park.
Traverse: This point-to-point FKT route is a traverse from the north end of the park at the parking lot [46.412783, 13.846675] next to the Aljažev dom v Vratih hut. The route quickly approaches the base of the north face and sustains a steep grade to the Triglav Lodge on Kredarica just east of the peak. From this hut, an extended via ferrata awaits on the climb to Mali Triglav and Triglav. On the descent, return to the hut and continue south towards Lake Bohinj, ending at Slap Voje Pavel Kozelj hut [46.329257, 13.877894]. There is a net loss of elevation on this route of about 300 meters. (You can do the traverse in the other direction, but it is likely to be slower due to more elevation gain.)
Although this is a memorable traverse, I see many other options such as a south to north traverse, summit only via Prag Route, ending at the Lake Bohinj beach, etc. Feel free to brainstorm with this idea - enjoy!