Everest Base Camp is a walking trek. There is no technical climbing and no glacier travel on the standard route, which is why thousands of people with no mountaineering background complete it every season.
What makes it hard is altitude and repetition. You will walk five to seven hours a day for twelve days, sleeping progressively higher, with a top night at Gorak Shep at 5,164 m where oxygen is roughly half of what it is at sea level.
Preparation that actually helps: three months of hill walking with a loaded pack, one long back-to-back weekend, and a conservative acclimatisation schedule with two dedicated rest days at Namche and Dingboche.
Preparation that does not help: gym cardio alone, buying an expensive pack the week before, or trying to shave days off the itinerary to save money. Altitude does not negotiate.