Okay, so yeah the original post was hard to read, that being said, here's some basic information that should help:
1. /pcmd add Player Name should in fact add anyone to your party. It took me a while to figure out this myself as it wasn't the exact same as ffxi. (why I do not know)
2. If you throw up your party flag, or use the party search feature, people can join your group directly from that without you needing to invite. This is why sometimes you will see people shouting in town for groups with the message 'join from search' etc.
3. If you are just returning, you might need to find a nice, social beginner ls. Here is a link to the 'Linkshells of Durandal' While it is not all-inclusive, between this and a lodestone search, you might find a group right for you. http://forum.square-enix.com/ffxiv/threads/38413-Linkshells-of-Durandal
4. Since you feel like a 'noob' with a high level character, it might be wise to start leveling one of your low level classes up. One, it'll help you get use to the game again, but two, it might help you meet other people, make gil etc.
5. If you have questions about gameplay etc, you might be better served using the official lodestone forums rather than here. Just try to be clear and concise about what you are asking. As the lodestone forums can ONLY be answered by people actively playing the game, (unlike here) the advice tends to be a little more updated and slightly less trolly. (although people would have been very confused by your OP regardless).
6. Level MRD...PLD is still only modestly saught after in game for parties atm. Edited, Jun 25th 2012 1:28am by Kinseykinz