As others have said, HydroGuy's DLR Guide for WDW Vets is a great place to start. Given that you've been to WDW that should help give you a sense of the similiarties and differences between the two resorts.
I'll echo what everyone else has said in that DLR is much smaller (as in, compact) than WDW. The two parks are only 110 yards apart, so park hopping is very easy to do. I like to think of it this way: imagine DL as Epcot's FW, DCA as Epcot's WS, the Esplanade that connects them is like the bridge between FW and WS, and DTD is just outside of International Gateway.
Can someone guide me at rope drop for both mornings where to go. We want to see all in both parks (minus screamin and astro orbiter in DL), anyone have some advice how to begin a plan?
Just to make sure we're on the same page, but Screamin' is in DCA and Astro Orbiter is in DL.
What to do first at DL depends a little on your priorities/interests. Like WDW, the Anna & Elsa line builds up fast and stays long all day. So if you want to see them, you have to be at the front of the rope drop crowds and head to their M&G area with all haste. Otherwise, Peter Pan also tends to have a long line all day long. If you are less interested in the FL rides, I would probably either head to Indy or Space and get a FP and then do some other rides in that general area until the FP time opens up. Space and Indy both tend to have long lines, so make sure to use FPs for them to save some time.
In terms of DCA, I would probably either head straight to TSMM (no FP for that ride at DCA and the line tends to stay long all day) and then come back for a RSR FP (probably mid-to-late-afternoon/evening return time at that point). You could also get a RSR FP first and then head to TSMM, but there will probably be a line at that point.
DLR is
not using FP+, so it's still the "legacy" system. They are enforcing return times, so you must plan accordingly. You can get your next FP two hours later or after the return window opens, whichever comes first. The two parks are "disconnected" from each other, but all FPs within each park are now "connected" (except WoC, which is still disconnected). This means you can grab a FP for a DL ride (e.g., Star Tours) and then go to DCA and grab a FP there (e.g., RSR) without having to wait for two hour or the window to open.