Order the thank-yous
Spend 15-20 minutes hereMost groom speeches open with thank-yous because the groom is, traditionally, speaking on behalf of the new couple. The order matters more than the words.
The standard order: thank both sets of parents (yours and your partner's), thank the wedding party, thank the guests for being there, and thank anyone who did real work on the day. Keep each one to one or two sentences. The room is patient through thank-yous, but not generous. Specifics earn the patience back: not "thank you for everything" but "thank you for the rehearsal-dinner toast last night, Dad, which I will think about for the rest of my life."
If you forget someone, the speech is over and you cannot retroactively add them. Make a written list before you draft, check it twice, and put the most important people in the most prominent spot in the order.