I had a lesson last night, and David pointed out that whatever the dynamics are I always play the 2nd octave loud and 1st octave quiet. Try as I might I couldn't get the 1st octave to sound LOUD. Help please.

, it is easier to get the 2nd octave to sound loud. To get the first octave to sound louder, support the sound with your diaphragm and use plenty of air.

Try turning your bottom lip in a bit to focus the air stream downwards. This will stop the note accidentally going up the octave. Experiment with your embouchure as much as you can until you find the right position.

Sigh... 2 frustrating hours spent trying alsorts to get some volume out of everything below A1. diaphragm support, stomach muscle power, varied embouchure, even varied headjoint positions. I've no idea what I'm doing wrong but I give-up for tonight. Lets hope tomorow brings a fresh approach and a solution.

Relax. Trying too hard will make this problem worse.

Also, as you point out in your signature, you are a mature-beginner-flautist. Things come in time.

Your embouchure has to be more relaxed to get the bottom octave - too tight & the notes will be shooting up an octave.
Does your teacher say anything about the size of the aperture of your lips - whether it's OK or too big. Imagine water running out of the end of a hose pipe - put your finger over the end of the hose to make the aperture smaller & the water shoots out faster although the tap's not been turned on anymore. I was told to hold the flute with my lips completely closed - so no sound when you start to blow, then let the aperture in your lips get slowly bigger until you just get a sound - remember how small that aperture feels & that's what it should be like to produce a focused stream of air into the flute

YAY! It's getting there at last..... lots of practice needed , but such a relief.
Ok, having to loosen my embouchure for ff 1st octave, much bigger hole (I had breath support, but was blowing too fast/narrow). for 2nd octave in pp embouchure is fine but blowing too fast, having to greatly reduce the air pressure.
Thanks for advice