Disneyland’s early entry procedures can be a little bit convoluted, but @lmbc is exactly right.
EMH= Onsite hotel guests only, for everyday of your stay including check-in & check-out. There will be one park available each morning (generally Tues, Thur, Sat are DL & every other day is DCA).
MM (Magic Morning) = Any guest who has purchased 3 or more day tickets in advance of arrival (ie not at ticket booths at Disneyland). You get 1 morning only and only applies for use at Disneyland when it is open early (generally Tues, Thur, Sat). So it runs concurrent with DL’s EMH for on-site guests.
If you are staying onsite, definitely absolutely 100% take advantage of EMH in DCA because it’s only open to onsite hotel guests and there aren’t very many at Disneyland Resort.
If you have the Magic Morning, I love using it for a 7am Magic Morning at Disneyland. My personal preference is Fantasyland and Peter Pan to start (Although if I’m not right in the first 50-100 or so people for Peter Pan, I go to Alice in Wonderland instead). At 7am Magic Morning though you can usually get a 20 min or less wait for Peter Pan which is the least it will be all day. I love to do Fantasyland first because there are no FPs for any of it and the walkways are narrow so coming back to navigate after crowds arrive is challenging & at times frustrating.
If Tomorrowland is more your speed, then Hyperspace, Nemo, Star Tours & are great Magic Morning priorities as well (but Star Tours & Hyperspace both do have FPs & I prefer Tomorrowland at night all lit up beautifully & with the Star Wars music fully piped through the speaker system so I only start here if we are itching for a Star Wars fix and will be in DCA or doing a specific nighttime show that prevents us from working in Tomorrowland FPs).