Hi,
Google Cloud Platform is a very good option for small/medium companies or startups as it helps avoid the upfront infrastructure cost and gives the ability to scale your applications as the size of the company grows. To see why you should choose Google Cloud Platform visit the link here.
Since you mentioned that you are interested in deploying PHP based framework apps, here is a link to article PHP on Google Cloud Platform that will help you to select Google Cloud Platform (GCP) product for your needs. The easiest way to start with GCP is to deploy your apps to App Engine. App Engine are fully managed serverless application platform. App Engine come in two variants App Engine Standard and App Engine Flexible. Read the article Choosing an App Engine Environment to help you choose the right environment for you. Applications on App Engine are built using the micro-services architecture. You can easily host applications for multiple clients either as multiple services in your project or as a single project for each client.
For databases there are a number of options that you can choose from. Cloud SQL , Cloud Datastore, Cloud Spanner, Cloud Memorystore. You can read about each of these in detail by clicking on their respective links.
To store static file(s), images etc outside your web server you can use the Cloud Storage service as well.
An alternative to deploying apps to App Engine is to deploy your apps to Compute Engine instance. Compute Engine is an Infrastructure as a Service. There is a sample tutorial for building a bookshelf app on Compute Engine using PHP.
In the documentation section of each product there is a Getting Started section that will guide to basics for that product.
You can see all the training options for GCP by following this link. The certifications offered by GCP are listed here.
To see complete list of products offered by GCP visit the link here.
Google provides both free and paid support to its clients. To see all options visit the link Google Cloud Platform support.
I hope this helps.