Installation articles are only required reading for the DM.
PlanarAlly does not have to be installed by each player, so if you're a player you can go straight ahead to getting started with PlanarAlly or the full docs over here.
As a DM you'll have to choose whether you want to host PlanarAlly yourself or whether you want to use an existing online service. Both approaches have their ups and downs.
Comparison of hosting options
It's important to be aware of the pros and cons of hosting PA yourself or using an online service. To give more insight we'll go over some aspects that differ between the two options.
Self-hosting is compared to an online service way more complex. Where an online service requires no installation at all, self-hosting requires some manual work. You'll probably need to read up on things like port-forwarding to give your players access to your server. If this sounds daunting feel free to contact me or simply opt for an online service where you won't have to worry about these things.
While self-hosting is more complex, it also offers you more flexibility. You can configure the server settings to your liking and tweak with the software as you see fit. Maybe you want to alter some colours or place a logo somewhere. These things are not possible when you're using a preconfigured online service.
That said, I expect most people to not really change much.
As an online service requires access to the internet, self-hosting is the only approach that offers offline support. You can start your server somewhere in a basement and your players can connect as long as they're on the same network.
Ideally it becomes possible in the future to export your session from online services, so that you can bring your files with you if you would venture into remote areas. But this is alas not yet possible.