Hi @Mcnfckmsft ,
I suggest you try PowerApps trial plan firstly.
This is valid in 30 days. Most functions are availabel in this plan. It is maninly be used to learn PowerApps. So it can only be used personal. "Sharing" and "environment" is not supported in this plan.
After you general understand PowerApps, you could buy a plan based on your demands.
Please note that the new license options will relase in Octor. I suggest you consider buying it when the new version relases.
Here's a doc about it for your reference:
https://powerapps.microsoft.com/en-us/blog/new-licensing-options-for-powerapps-and-flow/
Even if PowerApps is low-code platform, but you also need some skills about programing. So you need some time to learn it. However, it will be easier than other programing platform.
Here's a doc about how to use PowerApps in details for your reference:
https://docs.microsoft.com/en-us/powerapps/powerapps-overview
This is a really good learning doc.
Sharepoint is a data source that PowerApps usually use.
You could also use other data source. PowerApps supports a lot. Using sharepoint is not necessary. It's just an option.
Here's a doc about PowerApps supporting data soucre for your reference:
https://docs.microsoft.com/en-us/connectors/10to8/
Best regards,