Short answers, pulled from the story.
The Western Desert campaign began in the summer of 1940 with extreme environmental challenges including scorpion stings, heat, cold nights, and sirocco winds that reduced visibility to a few metres. The Maletti Group got lost leaving Sidi Omar because Bedouin nomads knew how to navigate by sun and star but Italian forces lacked this knowledge.
Operation Compass began on the 9th of December 1940 when Selby Force advanced from Matruh to isolate Maktila. Australian infantry broke into Tobruk at dawn on the 21st of January 1941 and captured half of the defences by nightfall before retaking it completely on the 13th of November 1941.
From the 9th to the 11th of December 1940, the British took 38,289 prisoners, 237 guns, 73 tanks, and about 1,000 vehicles for only 624 casualties. Later operations resulted in another 25,000 prisoners, 208 guns, and 87 tanks with losses of 355 Australian and 45 British troops.
Axis supplies failed because a German motorised division needed 100 tons of supplies a day while moving them 500 miles required 1,170 lorry-loads. The Italians had only 7,000 lorries for deliveries to their 225,000 men and truck non-serviceability of 35 percent reduced actual deliveries to the front significantly.
Adolf Hitler issued Directive 22 on the 11th of January 1941 ordering Operation Sunflower which led to raids at El Agheila on the 24th of March and Marsa el Brega on the 31st of March. By the 15th of April 1941 they had pushed the British back to the border at Sollum and besieged Tobruk before the Eighth Army offensive began on the 23rd of October 1942.