D.W.
If I had it to do over I would have gone with one-size pocket diapers. They will carry you longer and you can adjust the absorbency depending on nap/nighttime, etc. I like Bum Genius and Thirsties Duo. It is cheaper to go with prefolds and covers but also less convenient.
You do not want to leave your diapers to soak in between washings. This is hard on the fibers and will cause your diapers to wear out faster. It also becomes a drowning hazard not to mention really gross having a bucket of pee and poo water hanging around. You don't need or want to do this. All you need is a small garbage can with a lid and a large wet bag (this you will get from your cloth diaper provider). If properly cared for your diapers will last for the next baby further increasing your savings!
As far as poopies-if your baby is exclusively breastfed you do not need to rinse. Just toss in the pail. It will wash out. If baby is formula fed you might want to invest in a diaper sprayer that hooks to the toilet. When baby is older and starts solids you will want to use liners that are biodegradable. Makes clean up much easier. And there are some brands that can be washed and used again if baby only wet them.
Washing is easy-run a cold cycle with no detergent, hot wash with tablespoon of detergent that works with cloth diapers (I use Arm & Hammer Essentials Free & Clear), hot rinse if you have it but if you don't cold will work then a final hot wash cycle/rinse to ensure all the soap is out of the diaper. Everyone has their opinion on things like vinegar and baking soda. I've never found the need to use them and I've been cloth diapering for almost 2 years. Water is really the key to clean diapers. And yes, you probably will get stains. It's just part of the game. Some baby's have poo that doesn't stain and others it just does. Doesn't affect anything one way or the other.
Nighttime is easy! Just add extra absorbency when baby is older or sleeping longer periods of time. Use a thin hemp liner or two (as baby gets older) along with the inserts that come with the diaper. The inserts that come with the diapers are usually microfiber which is highly absorbent. Prefolds are not as absorbent for overnight.
You will want to wash every other day or 2 max. You will change baby about every 2 hours (of course that can certainly be more when baby is little) but you could probably get away with maybe 12-16 pocket diapers to start. But you will be washing probably every other day. But the washing is really no biggie. Or a couple dozen prefolds and 6 covers.
Some people use cloth while traveling some prefer to use disposables just to make it easier.
But you can also start the transition slowly-buy a couple types of diapers that you think you might like and try them before you invest all your diaper money in one type.
There is a learning curve but using pocket or all in one diapers is more like disposables so they are easier.
I like pinstripesandpolkadots.com and greenmountaindiapers.com for great diaper info and purchases. Green mountain have the gold standard for prefolds and pinstripes has pocket/aio's and really great customer service.