Foiling is a challenging sport to learn, and from my experience prior surfing experience doesn't help as much as you'd expect. However, there are certainly some things that will make the process as easy as possible, primarily the type of foiling you're doing and the equipment you have. Depending on what your goals are and what you have access to, I would say from easiest to hardest : Wake foiling, wing foiling, SUP foiling and Prone Surf foiling. If you have access to a boat, that will be the easiest way to clock some time up on foil allowing you to feel out the balance, turning, and even play with pumping. With a wing, you similarly can get a constant source of power, which is extremely helpful in feeling out the foil, and it also gives a large amount of stability holding yourself up against the pull of the wing. However the wing boards are bigger, and you have to learn how to use the wing first. All that said, both the wing or the wake will allow you longer and more controlled time on the foil which is critical to expediting the learning process. If you don't have a wing or wake, I recommend learning with a SUP foil before prone. The SUP allows you to more easily access obscure waves away from others, catch more waves, catch them easier, and lets you already be on you feet to control the lift-off of the getting up on foil. Once you're up on foil the smaller prone board is certainly easier to manage, but you'll clock so many more waves, equating to more time up on foil, that the SUP will significantly speed the learning process over the prone.
Now depending on your goals, where you live and what equipment you have access to, you may only be able to or interested in doing some of these. Just remember that like anything else it's all about repetition and time spent on the foil. Through whatever means, the more time you can spend up on foil the faster you'll progress, and when you're just learning it is much easier to get that time with a constant predictable power source. That being said, there is no replacement for learning how to catch a wave on a prone foil other than catching a wave on a prone foil, or using a wing for that matter. But it will be much easier to pull off if you are already familiar with riding the foil.