Should I use kaspaminer.exe to mine Kaspa?

No — kaspaminer.exe is a reference implementation and is not recommended for actual mining. The Kaspa node archive includes kaspaminer.exe, but it exists as a technical reference, not a practical mining tool. More efficient third-party miners are available and covered in the Kaspa Mining documentation. For a beginner, this matters because using an inefficient miner means earning significantly less KAS for the same electricity cost.