Systematic tasting does not require immediately identifying an elaborate list of fruits. Start by giving different aspects of the cup their own attention. Smell the grounds and brewed coffee, take a considered sip, then think about broad flavour categories before looking for a precise comparison.
Continue with acidity, sweetness, bitterness and texture. Ask whether the cup feels light or substantial and whether the finish changes after swallowing. Return to it as it cools. Write what you notice before reading the seller's complete tasting notes, which can otherwise become an expectation rather than an independent observation.
Keep the brewing recipe alongside those notes. A difference between two cups may reflect preparation as well as the coffee itself. Use familiar foods to build references and compare small numbers of coffees under similar conditions. The aim is a usable personal flavour record, not a performance of expertise or a requirement to agree with somebody else's description.
The conversation
A good question can make a better brew.