You'll see lines of uncles on the pier out on the east coast pulling max 5cm fish up, and keeping them in buckets of water until it comes time to leave, to go home and cook them. That might be why the are no 5cm+ fish!
You can do day charters here, out on a boat. It was discussed maybe a year ago, so worth a forum-search to see what you dig up.
Fishing is often really great fun. It requires learning new skills, tactics and choosing different gear, versus where you are fishing and for what species. So the overall sport covers many many different flavours.
I prefer sea-fishing over fresh-water. Especially the chance of a day out on a boat. My father grew up sea-fishing, at least weekly, but in later years he prefers the honed skills and patience required for freshwater fish, such the very very clever and elusive trout!
I'd say:
- Don't bother doing anything local/onshore-based the first time out.
- Either take a specific charter, or even better wait until you're on holiday and do so. Bali used to be a big-fish destination, I'm sure there are plenty of others within the region.
- If you're just starting out, choose an approach that should bring good results (i.e. several nice fish!). The alt. could be several days baking on an East Coast pier catching nothing; and the shame there, is you might decide to never go fishing again.
'Tight lines!'