I'm going to Busan for 3 days and 2 nights, please give me some tips

I'm planning a trip to soak up the atmosphere of the Busan International Film Festival (BIFF),
but I have no idea what the weather will be like.
Should I pack short sleeves with a shirt? Short sleeves with a cardigan? Or just long-sleeved knits?
I want to minimize my luggage as much as possible,
so I'm curious about what people are wearing in Busan these days.
Also, I managed to get round-trip train tickets but couldn't find accommodation,
so I'll just be sleeping at an acquaintance's house in Busan.
They said it's in the Yeongdo area, but there are no subways or buses.
Does that mean I absolutely have to take a taxi?
I'm planning my itinerary with a ratio of about 70% Busan travel and 30% film festival vibes.
Here is the itinerary ChatGPT made for me:
Day 5: Arrive in Busan → Drop luggage at friend's house in Yeongdo → Late lunch → Yeongdo/Huinnyeoul + Nampo. The BIFF Eve event is an optional choice depending on time and energy.
Day 6: This day is all about freedom from BIFF lol. Visit typical Busan spots like Haeundae or Gwangalli, go to cafes, and visit famous restaurants. Just hang out without a fixed schedule.
Day 7: This is the only BIFF Day. Move leisurely in the morning, head to Centum → Focus on the "Possible Love" open talk → Busan Station → 18:32 train.
This way, it feels like I'm enjoying the film festival while traveling Busan, rather than just squeezing the festival into a Busan trip lol.
It suggested this—does it look okay?