In all honesty after a break that spans such a large swathe of expansions and game changes you would probably find it easier getting into another MMORPG than catching up on the EQ express. That's not what I would recommend though. The depth of EQ is dificult to match, and if you can jump back in then I think you will be pleased with many of the changes that you come across (after the learning curve starts to lessen

).
To help you understand some of the changes that have occurred since you left I would suggest you look through the information that Samanna has collated and made available via the drop down lists at the top of these pages. in particular is a good one to view, detailing the expansions and the key aspects introduced by each one.
Being level 65 with a good core of AA is a great place to resume from (56 AA is a great foundation in my opinion, though it does of course depend where you spent those - smile). Whilst your equipment is undoubtedly a little low by todays standards you have returned at a point where huge upgrades have never been easier to obtain. I would strongly suggest that you look for a friendly casual guild to join though. Not only will they be able to help you learn the new ropes, but they will also provide a mutual support infrastructure whereby each of you can help the others in game and equipment progression. We're all different but I know that in your shoes I would become frustrated and a little bewildered at the huge scope of the game if I didn't have that sort of support.
Henora's link to hunting spots is well worth reading, however it's worth mentioning that to take advantage of the majority of those zones you will need to invest in the new expansions. More good news for you in that SoE has released all of the expansions in one upgrade pack (with the exception of the latest - 'Prophecy of Ro' - a very interesting expansion but one you can live without for the timebeing). Look out for the Everquest Titanium pack - I think it sells for $20 or so, and can be used to either start a new account, or as in your case 'patch up' an existing account to include the new expansions.
To answer some specific questions that you had - yes you are looking in the wrong zones (I remember a profound sense of loss when I returned after a break and was running through East Commonlands after the bazaar had opened - 1 player in zone - me. I would imaging you feel much the same). Omens of War is a great expansion for the level 65+ character, and you will find many of your peers either there or in the subsequent 'Dragons of Norrath' expansion zones. EQ may be dieing (slowly) in terms of playerbase, but it still has many years of life left and many many people for you to interact with.
I don't think you've mentioned which server you are on. I'm not the most experienced Shaman, having just dinged 70 and not been interetsed in more than modest raiding, but you are very welcome to send me a tell if you spot me online (UK timezone). Cross server tells are possible nowadays, just do:
;tell antonius.katt Hello
...and I'l hapilly chat
Katt