Hi Zed
Good advice from both Paul and Mike above.
The sliding clicky thing on the reel is best left off as most anglers find the noise very annoying. The only time we use it on our boat is if the rod is put in a holder and left to fish itself. The idea is that you get you tackle on the bottom fishing set the ratchet and either put the reel out of gear or if resistance isn't quite enough leave in gear and back off the clutch until the reel stays put without letting off line in the tide. When a decent fish comes along it will pull line from the reel with the ratchet giving an audible alarm of some activity. If /when this happens pick up the rod, turn the ratchet off, either turn the handle to engage the gears or tighten the clutch up to a pre-determined point (not locked up) and play your fish.
I would strongly recommend the use of braid especially if you intend to go offshore any distance however as braid has no stretch you will need to set your clutch slightly lighter. The reason for this is that mono with its stretch (typically 30%ish) gives you a kind of added buffer that you do not get with braid. Either a slower action rod or less clutch/drag is needed to compensate for this. Do use backing line of about 20-25lb and nearly fill the reel, leave about 8/10mm of room on the spool to take your braid. The 6500 is a lightish reel so I would suggest you load it with about 200meteres of 20-25lb braid. After a seasons use you can reverse the braid to get another year out of it. Ordinary knots are not that good in braid and as Mike posted try the albright or get a member to show you their preferred knots.
Martin