The following links are about moving fish and tanks across country by car.
https://www.fishforums.net/threads/moving-to-london.453752/#post-3832026
https://www.fishforums.net/threads/how-to-move-60-gallon-tank.451650/#post-3814570
-------------------------
Feed the fish a little more often for a couple of weeks before you move.
Do a 75% water change and gravel clean every couple of days for 2 weeks, before you move. This will clean the water and substrate and make it cleaner when you actually move the tank.
Make sure the new water is free of chlorine/ chloramine before it's added to the tank.
Clean the filter a week before you move.
Do not feed the fish the night before you move, or on the day you move. Don't feed them until the day after you have moved.
-----------------------
Get a couple of large plastic rubbish bins or buckets with lids (45 or 70 litre bin). Fill them 1/2 to 2/3s with tank water and put the fish in them. I would probably put the 2 big goldfish in their own buckets, the smaller goldfish into another bucket, the Betta in a bag of tank water or bucket of water with the plants, and the cichlids into another bucket/ bins. Seat belt the bins into the back seat of the car or somewhere they can't tip over. Use the seat belts to hold them in place if you can.
Get a power inverter for your car, you can pick them up from an auto store. They plug into the cigarette lighter and you can run normal electrical appliances off the car battery. They convert 12volt power to whatever your country uses, and have a normal power socket.
Connect a normal aquarium air pump to the power inverter and run an airline and plastic multi-coloured airstone into the buckets of water with the fish. Try to get the multi-coloured airstones with the lead weight in the bottom section. They stay down instead of floating around.
If you can't get a power inverter, then look for some battery operated air pumps. You can buy them from fishing shops, pet shops or Ebay. They are often sold as bait pumps. You get single outlet and double outlet types. Some use 1 battery and others use several batteries. Some plug into a cigarette lighter.
If you are really stuck for air, use a normal airpump while at the house, and then run a length of airline from the bucket to the front seat and blow bubbles into it yourself. You don't need to blow air into it all the time but do it every couple of minutes and that will aerate the water during the trip.
-----------------------
On the day of the move, put the fish into their buckets of water and add an airstone to each bucket. Keep the fish buckets in the house until everything else is in the car. Then put the fish in last.
Empty the aquarium and put the gravel into buckets.
Put ornaments in a bucket.
Pack up all the fish gear and put it in boxes and put them in the car.
Put any plants in a bucket of water.
If you have a power filter, clean the filter materials and put them in a bucket with some tank water. You only need a 1/3 to 1/2 bucket of water for the filter media. Keep it in the shade so it doesn't cook.
Rinse the tanks and filter case out under tap water, dry and put in the car, truck or trailer. Keep them shaded so the sun doesn't crack the base of the tank.
Put the tanks on a blanket or foam mattress and put some pillows around it to stop it moving. Do not have anything in the tank while it is being moved.
If you have coverglass, put them on the empty tank and sticky tape them in place.
If the weather is hot, have the car's air conditioner on so the water doesn't heat up and cook the fish during the trip.
-----------------------
If you are moving a lot of tanks and have some time to move them, move the fish out of half the tanks and put them in your other tanks. Empty their tanks and move them, set them up and come back for all the fish. Move the fish into the tanks at the new house, then come back and move the remaining tanks.
If you have to move a lot of tanks over a large distance, get plastic bins and put the fish in the bins with an airstone. Empty the tanks and move them onto a truck. Put the fish in a car or truck with aeration. Go to the new house and set them all back up.
-----------------------
When you get to the new place, put the tank in its spot and set it up using the water you took, then top up with dechlorinated water. If you take several buckets of tank water you should be able to partially fill the tanks with their old water, add the fish and filter, then top up the tank with clean dechlorinated water.
Get the filter running asap and monitor the ammonia and nitrite levels for the next month. If you get any readings, do a 75% water change to dilute it.
Keep the feeding down to a couple of times a week until the filters have recovered.