From the graph you've provided:

1. To find $f(0)$, you look at the value of $y$ when $x = 0$. Observing the graph, $f(0)$ occurs where the line crosses the y-axis, which is at $y = 4$. So, $f(0) = 4$.

2. To find $x$ such that $f(x) = -1$, locate the point on the y-axis where $y = -1$ and determine the corresponding $x$-value. In the graph, this occurs at $x = 6$. Therefore, when $f(x) = -1$, $x = 6$.

Let me know if you need any further details or have other questions about the graph or function!

Here are some related questions you might consider:

1. Can you explain how the slope of the graph affects the values of $f(x)$?
2. How would the graph change if $f(0)$ was a different value?
3. What would the equation of this line be based on the graph?
4. How can the intercepts help in sketching the graph of a linear function?
5. What are the implications of this function being increasing or decreasing?

Tip: When trying to find a specific $f(x)$ value from a graph, always ensure to read the value precisely where the function line intersects with the corresponding y-value.