Hi Lilly,
To help guide your procedure making, I'd encourage you to review the definition of buffers and why they are so useful. (From Chem Libre Texts Intro to Buffers) - there are some good pictures showing how you will be able to tell if you have a buffer.
A buffer is a solution that can resist pH change upon the addition of an acid or base. It is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable. To effectively maintain a pH range, a buffer must consist of a weak conjugate acid-base pair, meaning either a weak acid and its conjugate base, or a weak base and its conjugate acid. Because there are different combinations, buffers can be at various pH ranges.
If you have done titrations in lab, you may have had to plot the volume of titrant added against the pH or seen them in lecture. It looks like a steady increase and then there is a sharp jump up past the equivalence point.
A buffer is able to resist pH change because the 2 components (conjugate acid and conjugate base) are both present and are able to neutralize small amounts of other acids and bases (in the form of H3O+ and OH-) when they are added to the solution. This buffering action can be seen in the titration curve of a buffer solution.
Because a buffer can handle both acid and base, I would advise you to run a trial with each as a titrant and then plot it. This should help you determine the buffer's working range.
