What is the general architecture of a network that comprises of Web Application Firewall(F5), Firewall, VPN, reverse proxy(nginx)?
I am new to this field and I am wondering what the architecture in general looks like? And where can I learn more about this? Any courses or certification exams that I can do to boost my network architecture skills?
That's a broad question. Generally, architecture is a description of the solutions in place and how they interact. There's a level of detail to the documentation for a solution:
Architectural Handbook (AH): a high-level view of the solutions, providing guiding principles for the deployment. Should initial design choices run into difficulties, use the AH to provide guidance in how best to resolve those difficulties.
High Level Design (HLD): Details hardware and software to be acquired along with licensing, where it will go, how it will be rolled out, and system settings to be used.
Low Level Design (LLD): Specifies on an interface level how things are to be connected. Often a set of network diagrams with explanatory notes.
In the Americas, the documents tend to be brief. In Europe, they tend to be larger and more wide-ranging.
That being said, the architecture for you scenario would specify the order the devices mentioned would be arranged. We'd want to know more about whether those are running on separate platforms or on the same one. Also, is this for accessing an external-facing application that is exposed to the Internet, or is this for access to an internally-hosted application that is not otherwise exposed to the Internet? Those answers will determine how the pieces fall together.
To boost architecture skills, ask more questions and get more answers. Architecture involves learning about many different technologies so that you have a range of tools to draw upon when asked to solve for a particular business case.