Hi Jason fellow language learner here!
" I don’t know how to start off the right way to make enough room for a lot of words, or how to connect memory palaces to each other etc. "
Here’s what I’ve done hundreds of time. Real example :
In my memory palace, instead of adding my new piece of dialogue (don’t place seperate words, place pieces of dialogue, if you want to focus on learning how to speak as fast as possible, and pieces of dialogue = grammar included, so no need to have seperate journey’s for grammar alone) and you’ll be able to say what you need right away.
So to address this problem, which isn’t really one when one realizes the number of palaces one can create is infinite, I jump to another familiar place by going to the first place that comes to mind when thinking of the new bit of dialogue to place. Example:
Do you come from America ?
first image that comes to mind : GUM … imagine a big piece of slimy green gum.
DON’T WORRY, trust me, with numerous recalling and revisions necessary for long term memory, and one’s natural ability to cancel out any other possibilities with the help of the rest of the content in your palace, you’ll remember that that’s the “Come from America?” question.
So
First familiar place that comes to mind:
corner store 
where I used to buy my gum when I was a kid.
I then firmly place my giant gum where I am at the moment, in this case my hospital cafeteria already full of the most basic of Arabic dialogue,
and that reminds me to go to my candy store
In my , I encounter A huge burning pitchfork shaped HOT Gum candy 
carried by thousands of ants out of the store (first station, the entrance)
What is the burning pitchfork for? And the ant’s? 
?
HELL Ant amin America ? Which is what “do you come from America” in arabic sounds to me.
You could ad a giant odourfull MINT candy if needed ONLY IF on recalling the first times going through the journey the ant MIN doesn’t come to mind. But to my experience, two images is enough for a three or four images dialogue. Oh wait! I already made the gum green ! Green mint gum… Easy peasy!
Remember, for long term memory, even with a memory palace, it’s necessary to go through it often, the best time being right before you feel you will forget some of it. Right away after creating, 20 minutes or so later, right before going to sleep, next day, in 3 days, in a week, etc. But I find going with my feeling works best than doing a revision at specific intervals.
Remember, you need the audio for this as long as you don’t master the pronounciation and writing, so become a parrot and go through your journey listening to the audio, repeated and working on your ear development and mouth and throat development for pronunciation. Try to exaggerate every sound as much as you can. After the first two or three recalls, I usually don’t need the audio and go on recalling with my own pronounciation and even sometimes my own recordings where I fit my audio to my palaces. I always need to tweek my palace adding an image, ignoring another when no longer needed, creating new portholes to round up a collection of dialogues thematically or grammatically… Sky is the limit once you develop the basics!
hl 'ant min amarika ?
No need to make things more complicated at first, starting small and not being afraid to make mistakes AND having fun have been my favourite tricks for success with memorising. Further on, modifications, add-ons, etc. Started coming naturally to me, as my skills grew.
Can’t wait to see what example you can share with us, I would love to here it.
Cheers,
a rocket to the Caribbean!
Or a crib made of rock
or a Saddam Hussein in a Johnny Depp pirate of caribbean costume!
arak qrybaan! See you soon !