You need to tell your system where Hadoop and Java are located. Edit your ~/.bashrc or ~/.profile file:
While Hadoop 3.x is the current standard, version 2.9.2 is still relevant for: hadoop 2.9.2 download
Apache Hadoop 2.9.2 remains a significant milestone in the Hadoop 2.x release line. Known for its stability and the introduction of critical features in YARN (Yet Another Resource Negotiator) and HDFS, it continues to be a go-to version for organizations maintaining legacy big data infrastructure. You need to tell your system where Hadoop
tar -xzf hadoop-2.9.2.tar.gz