0-3 months
Starting with a newborn
Newborns tend to sleep a lot, feed and pee very frequently and overall are very sensitive to change. It's a great age to start toilet learning as they're very sensitive to feeling wet, don't move much (limiting mess), open to learning the norms of life, and their capacity for distraction is limited. Being vulnerable and very new to this world they are keen to communicate when they need something and you are likely to be observing their every move intensely.
Some newborns may be uncomfortable with the new sensations as their gut starts to work. They may cry because they feel the urge to go, are going, or have gone and feel wet. It is up to you to support them (via trial and error) to be comfortable so they know you are there for them, aware of whats going on for them and are looking for ways to help them.
Many people don't feel confident holding a very young baby in any other position than 'normal' so if you prefer to use a nappy to start with that's entirely OK. In fact, it is a great time just to do some observation and teach them the sound association once in a while.
Use the best nappy for the right situation
Newborns are very sensitive to feeling a wet bum so if you use a cloth nappy with absorbent fabric they will likely squirm to let you know they're wet as soon as they need changing; so they are a great option when you are at home and nappy changes can be immediate. Many modern cloth nappies, especially pocket nappies, now have 'feel-dry' fabrics which means your baby is likely to be comfortable even if its been used and so that's a good nappy to use when an immediate change isn't always possible (e.g. when in daycare). Disposable nappies, with their 'super feel-dry' design, are best reserved for rare occasions when their high-absorption feature is really necessary (e.g. at night to prioritise sleep, or maybe when you or baby are sick, or your baby is accompanying you to an important meeting). Constant use of disposable nappies tends to desensitise babies to not take notice when they're peeing/pooing (which will require retraining later).