Given the function $f$,
\[
\begin{array}{r}
f(x)=2 x-7 \\
f(-3)= \\
f(3)= \\
f(-a)= \\
-f(a)= \\
f(a+h)=
\end{array}
\]

Step 1 ：First, we need to understand the function $f(x) = 2x - 7$. This is a linear function, where $x$ is the variable, $2$ is the coefficient of $x$, and $-7$ is the constant term.

Step 2 ：To find $f(-3)$, we substitute $-3$ for $x$ in the function. So, $f(-3) = 2(-3) - 7 = -6 - 7 = -13$.

Step 3 ：To find $f(3)$, we substitute $3$ for $x$ in the function. So, $f(3) = 2(3) - 7 = 6 - 7 = -1$.

Step 4 ：To find $f(-a)$, we substitute $-a$ for $x$ in the function. So, $f(-a) = 2(-a) - 7 = -2a - 7$.

Step 5 ：To find $-f(a)$, we first find $f(a)$ by substituting $a$ for $x$ in the function. So, $f(a) = 2a - 7$. Then, $-f(a) = -(2a - 7) = -2a + 7$.

Step 6 ：To find $f(a+h)$, we substitute $a+h$ for $x$ in the function. So, $f(a+h) = 2(a+h) - 7 = 2a + 2h - 7$.

Step 7 ：Finally, we check our results. All of them are in the simplest form and meet the requirements of the problem.