You're procrastinating, young lady.
I'm not a mum, but putting on my stern mum voice, and telling you the exact lessons my parents taught me.
When you have animals, you put their needs first before yours. Before we were allowed to get a pet, we had to research everything we could about them before we were allowed to even consider it. And this was in the days before internet access at your fingertips, so it meant reading my parents reference books, getting out library books, talking to other people who kept the same kind of animals, meet some in shops etc, and be totally sure we could provide what the animal needed, for the lifetime of the animal. They'd make us prepare like a report before they'd even consider letting us get a pet.
Research included - compatibility with the other pets. What housing/habitat does it need as a young animal, and once it's full grown? A newfie puppy is adorable, but you have to consider how massive they get as adults, and the extra care and shorter lifespan involved. Things to consider when getting a new animal. Is everyone else in the house on board or at least, not put out by the pet. No allergies/phobias etc, so my brother couldn't have a snake, my mum was nervous about them, and he didn't demonstrate enough responsibility or have space for a large snake.
What diet does it need, can we access and afford it?
Vet care expected?
Cost of the habitat/where do we keep it?
Is it a social animal that needs friends, or solitary?
Lifespan?
Can you commit to the animal for it's lifespan?
And the answers had to be honest, we had to be prepared to do all the care it needed ourselves (although of course our parents helped when there was a problem, or looked after the animal if we had something come up and couldn't for whatever reason that day).
Right now, you're thinking of the tanks and their inhabitants more like decor, or new projects you want to daydream about. That's not cool when you already have tanks that you're not taking care of by yourself, but relying on your parents to do the hard work for you.
Stop. You can't do justice to the daydreaming tanks, if you're not willing to get stuck in to maintain the ones you have. Tanks take work to make and keep them beautiful, even "natural scapes" don't just get like that by accident, and maintain water quality all on their own.
When we got up in the morning, got home from school, got home from activities - animal care came first, before any of our own wants or needs. If the pet needs cleaning out, that gets done before we could relax and play computer games saying we'd do it later, or have a nap/snack, not when the animals needed feeding! Pet care first, your own needs second. It's the responsibility you take on when you have pets, and your parents won't always be around to do the hard work parts for you. Trust me. As an older woman who has now lost both my parents, you'll thank them one day for teaching for responsibility and life lessons.
The fish and inverts you have now are living, feeling creatures, not just pretty decor. Poor water quality will stress, and eventually kill them. You're on holiday from school now? Then clean the tanks out, do the water changes, gravel vac, filter cleaning/glass cleaning, etc.
Do the necessary first. Then you can daydream, plan and sketch out what ideas you have for other tanks. But it's pointless to do that if you're not caring for your current tanks.
A typical plastic kitchen jug, or even a pyrex one, is not heavy. You can get buckets and bins that are on wheels that you could fill, warm, declorinate, then roll to the tanks, if they're on the same floor. Where there's a will, there's a way, and if you can't move 2 gallons of water at a time, or lift a jug of water from a table top bucket to the tank, or vice versa, then you have serious health issues, I hope that's not the case?
These two videos are very helpful for learning how to gravel vac properly, and control the flow of the water through the syphon. In the video, Cory crimps the hose to pause the flow, but I prefer just sticking my thumb over the end that's in the bucket when I want to pause the flow to move the syphon or avoid fish/shrimp etc.