If you park in Mickey and Friends garage, tram will drop you in DTD. You backtrack into DTD rather than head towards the parks and you can either cut through the Grand Californian Hotel Lobby which is just past Jamba Juice then out the front of the Grand and across the street or walk all the way through DTD towards the
Disneyland Hotel and turn left at Earl of Sandwich to the PPH Hotel.
If you park in Toy Story Lot...same thing, you just have to walk from the bus drop off, through checkpoint at the Esplanade then over to DTD.
Grand Californian route is fastest by just a bit, DTD route allows you to see all of DTD. Since you are new, go in one way and out the other so you get to check out both DTD & the Grand lobby. (Exit the BACK of PPH Hotel to get to the DTD walkway towards the DLH, exit the front of the PPH to cut over to the Grand)
Unlike WDW, everything in DL is literally a stone's trow away by comparison.