Sites promising a "free download" of the full Pro version with "all decompilers" are nearly always providing pirated copies.
Hex-Rays now offers a robust Free version of IDA that includes a cloud-based decompiler for x64 and ARM64. It is the safest way to learn the IDA workflow legally.
The latest version of IDA Pro, version 7.0, brings significant improvements and new features to the table. One of the most notable additions is the Hex-Rays decompiler, a module that enables the decompilation of binary code into a more readable, high-level programming language.
Downloads marketed as "exclusive" or "free" on third-party sites often carry significant security risks, such as malware or backdoors, which can compromise the sensitive environments typically used for reverse engineering. Official Free Options from Hex-Rays