"Special areas" in Disneyland that evoke Walt? Well, the whole darn place evokes Walt, because it was planned and built by Walt and his hand-picked team of Imagineers. Stop and look at the Mark Twain, and realize that Walt sold his Palm Springs vacation home in 1954 to get the money to build that boat in time for opening day in '55, as but one example.
All of Disneyland is Walt Disney's Magic Kingdom, quite literally. Unlike Magic Kingdom Park in Disney World that was built by a committee of a big corporation five years after Walt had died.
There are lots of little things and spots that Walt and his family created or had a hand in. The petrified tree in Frontierland was an anniversary present from Walt to his wife Lillian in 1957. Walt found the petrified tree in Colorado while filming one of his popular True-Life Adventure films, and he bought the tree from the man who owned the property and had it crated up and shipped to his home in Holmby Hills as a present for Mrs. Disney. Mrs. Disney opened the crate on their anniversary and she said "What is this?!" and Walt told her it was full of petrified opals and that it would look good in her rose garden. Mrs. Disney would have none of it, and she told Walt she didn't want that thing in her rose garden and he could send it down to put in his park, which was probably his plan all along. The tree was installed near the Rivers of America later in 1957 and the brass plaque identifies it as a "gift from Mrs. Lillian Disney". Stop and admire the petrified tree, and thank Mrs. Disney for having the good taste for saving her rose garden but plussing up the park.
The espresso machine in Café Orleans? Walt and Lillian found that on a scouting trip to New Orleans, Louisiana while they were planning New Orleans Square in 1965. Walt had it put along the prominent back wall of Café Orleans in 1966, where it remains to this day.
Disneyland is full of Walt tidbits and history and nooks and crannies. It's his personal theme park, not a clone designed by corporate committee after his death. And if you only have one day and will be skipping DCA entirely, you should probably do some online research to seek out those Walt items in the park since the Walk In Walt's Footsteps tour will eat up too much of your short single day visit. Good luck!