giving a big speech in a few days, give me your best advice

I just graduated from high school last year so this will be my first "real" speech ever

Well with public speaking the usual 'be present' bla is a bit special because that adrenaline rush you feel before you step on stage, that's your fuel. Embrace it and when you speak it turns into charisma and you rock the stage with hotness. Very obvious advice but no matter what you do the anxiety is always going to be there so when speaking I prep and visualise obsessively with the goal of how awesome the speech will be, but not focussing on reducing the anxiety. (Actually this does reduce it a bit because there's a very clear plan your brain can fall back on, if any little hiccups do occur 'in-field' :p)

Know a top sales guy who says a similar thing, the nerves are good because it means you care about it. If there were no nerves it would be a flat speech like a pancake. And nobody wants pancake speeches

I just read an advice that worked for a chic performing in a funeral, where she didn't want to be emotionally effected by the guests. The author adviced her to look at the audience foreheads, that way you won't be effected by peoples reactions to you speech

^ Yeah you can be giving the best speech ever and people's faces stay completely frozen, their "reactions" are zero indication of how well it's going. People are in waxwork mode

Tell us how the speech went

Do some vocal drills beforehand. Practice deep rhythm breathing