How a project gets from commit to cluster is explained under Deployments. Roles, application scope and the audit log are described in Security & access.
If you equip clients with the same stack every time, such as a CMS per client, describe it once as a pipeline; see Tenant pipelines. What it costs is listed under Pricing: two clusters from €99 per month, unlimited projects and users.
WordPress from the app catalog walks through creating a WordPress site from the app catalog; the post WordPress on Kubernetes: seven traps between the chart and the first page covers the pitfalls of doing it yourself.