High level advice is...
Start at a high level.
You said your tasks are "automation" and "development."
At the highest level, automation is taking a task that someone or some team is able to do by hand, determining the repeatable parts of it, and figuring out how to tell a computer to do it. Where does the data come from, how does it get fed to the computer, what does the computer do with it, what comes out.
Any kind of development is going to include where the program(s) will live, where the data will live, and how data comes in and goes out.
What resources are available to you for storing programs and data? If you don't have them, who can provide them to you? How do you request them?
I will say it's intimidating to be in an architect or CTO role, and maybe you're too close to those roles for your experience level. It takes some experience to have confidence in the decision-making role. (What technology should I use? What infrastructure should I use? How much time and effort has to go into making sure things don't break later - source code control, tests, test data/test environments, etc.?) If you're being faced with these questions, is there anyone you can go to that might already have an idea about what the potential solutions will include?
Almost everything can be broken down, and each individual piece can likely be overcome with a technical solution (along with the necessary business knowledge.) But taking it all as a whole is likely overwhelming, and each piece will take time to learn and understand properly. Maybe you were put in a place where you are not set up to succeed. Figure out if you can work around that, or need to find a better fit.