God's plan does not change with regard to Moses, but Moses changes to align with God's plan (Exo 3:7). God's plan is personal, historical (relates to a set time and event), geographic (the right place), operational (requires deeds, actions), motivational (God wants us to be motivated by love 2Co 5:14), inspirational (the Word of God is our inspirational power), and is unconventional (Isa 55, Psa 103). Our weakness (insufficiency) is the key to benefiting from God's strength, sufficiency (Exo 3:11, 2Co 12:9-10). Moses failures where do to trying to do the right thing at the wrong time and wrong way (Act 7:22-25, Exo 2:11-15). Moses' wounds from past failure come out in his conversation with God; he pleads inadequacy (Exo 3:11-12), and ignorance (Exo 3:13-14, Act 7:22). Moses expresses frustration and bitterness. God responds by telling of His vital role, and promise (Exo 3:14-22). Moses excuse of being rejected (Exo 4:1), makes God more abrupt; He gives Moses signs (Exo 4:2-9). Moses denies his skill (Act 7:22, 1Co 2:1-5, Exo 4:10), and refuses to go -- his bitterness (Exo 4:13). God's anger at Moses comes out (Exo 4:14). God forces Moses to speak through Aaron (divine sarcasm - as Aaron was not nearly as skilled - Exo 4:15-17). Moses does overcome, of course (Deu 33:1). This should be an encouragement to us.
After 40 years in the Egyptian palace then 40 years in the desert then 40 years leading Israel to their land Moses' life can actually teach us about living in the time we live.