Just to be clear, if you are staying at Marriott's Laguna Cliffs Resort you're not staying in Laguna Beach; you're staying in Dana Point, CA so you'll have about a 6-7 mile drive up Coast Hwy. to Laguna.
There is some shopping at Dana Point Harbor which is right below your hotel but it's not extensive.
Not knowing what you are shopping for it's kind of a guess but, as stated above, Laguna has very nice botiques and galleries for shopping. You can go to : www.lagunabeachinfo.com for some shopping ideas.
Also, as syrahgirl mentioned above, Fashion Island is a terrific shopping venue both from a shopping standpoint and as a visual, comfortable, social experience. www.shopfashionisland.com for a list of stores and restaurants. Fashion Island is approximately 15 miles north of Laguna Cliffs.
Additionally, there is South Coast Plaza in Costa Mesa which is 'upscale' shopping that can match Rodeo Drive. www.southcoastplaza.com
By this time you're getting about 20+ miles north of your hotel and, if you are driving down the I-405 (you didn't say) you may want to consider shopping on your way to the hotel rather than driving back to any of those shopping areas---just a thought.