I have read plenty on how it happened and what came later, but I haven't really found the reason for the war to begin with. What were they trying to accomplish? What were they planning to do had they won?
The goal was mainly to retake land captured by Israel in 67. This was meant to be achieved by putting pressure on Israel and the US to enter diplomatic negotiations through the 1973 offensive. You can see this in Egypt's first objective to push 13km into Sinai and stop, which was meant to be a show of strength and prove the Egyptians could still be a threat to Israel, hence a diplomatic solution would be best. I should add that stopping the offensive also kept the Egyptian ground forces within the range of their AA guns but that wasn't the main reason for them digging in initially.