Start your day by enjoying breakfast anywhere at the Pearl; there are many restaurants available and I highly suggest walking around to experience the neighbourhood fully. Then, head to Katara Cultural Village and Galeries Lafayette for the ultimate shopping experience; you can also find various local brands.
If you want to have a glimpse of Qatar's stadiums, take the Metro and head to Aspire Zone. Then, for some more shopping, go to Villaggio Mall, where you can find luxury boutiques such as Panarai, Bulgari, Valentino, Gucci, Celine, Bottega Veneta, Dior, Tomford, Luis Vuitton, Fendi, YSL, and many more as well as many other highstreet brands.
Next on the list would be Mall of Qatar, also easily accessible by Metro, where you can also find various luxurious brands.
And we shouldn't leave out Doha Festival City, where you can find Harvey Nichols.
For dinner, I would recommend Toro Toro in the Marsa Malaz Kempinski at the Pearl.