Kensington is a very nice base for this walk. You can enjoy some classical music in Royal Albert Hall if you are lucky to have secured some tickets for the BBC Proms. Hyde Park is only a 20 minute walk from Westbourne Terrace, where Park Grand London Hyde Park Hotel is located.
If you are coming to London by car, be aware of the Congestion Charging Zones and parking charges. Some hotels can offer you a complimentary parking space while some can charge you £25 for 24 hours. You can get good deals on parking via JustPark but make sure you book your space in advance of 2 hours before you needing the space.
Hope you enjoy this walk, its one of the most inspiring and romantic walks you'll ever take in London.