Back when the park opened there used to be an entrance across from the PPH that let you in DCA around Goofy's Sky School. That has been closed for years. The quickest way is to walk across the street and enter the Grand Californian Hotel. From there you can go through DTD or use the direct entrance to DCA.
If you want to use the DCA entrance, keep you receipt from Surf Up and that will give you access to that entrance if you are not a resort guest. Before 10 or 11am they restrict that entrance to resort guests or restaurant patrons only. Anyone can cut through the GCH to DTD though.
Keep in mind that Condor Flats area just outside the hotel and around Sorin is currently under refurb and closed off...meaning if you want to go to DL first, DO NOT use the DCA entrance and try and cut through...use the DTD entrance. If you enter DCA from the GCH, you only option is to turn right and head back towards Paradise Bay