Welcome to the Community,
ESXi is a bare metal Hypervisor which installs directly on the hardware. It's designed for server hardware, so you may run into issues when trying to install it on PC hardware (e.g. incompatible NICs, ...). If you just want to evaluate/try ESXi you can easily install it as a virtual machine in e.g. VMware Workstation, provided the host meets the Installation Requirements
André