解: (1) 0,1,2;
(2) 第$n$个等式为$2^n - 2^{n-1} = 2^{n-1},$验证:左边$= 2^{n-1}(2 - 1) = 2^{n-1},$右边$= 2^{n-1},$左边=右边,等式成立;
(3) 设$S = 2^1 + 2^2 + 2^3 + \cdots + 2^{2024},$由
(2)知$2^k = 2^k - 2^{k-1} + 2^{k-1},$则$S = (2^2 - 2^1) + (2^3 - 2^2) + \cdots + (2^{2025} - 2^{2024}) = 2^{2025} - 2^1 = 2^{2025} - 2$