Data types have no alignment restrictions. However, extra memory cycles might be required for the x86 processor to properly handle misaligned data transfers.
The x86 processors use little-endian byte ordering. The least significant byte (LSB) of an integer is stored at the lowest address of the integer. The most significant byte is stored at the highest address for data items in this processor. For example, byte 7 is the most significant byte for 64-bit processors.
Both Intel Corporation and AMD publish a number of books on the x86 family of processors. See Intel Home Page (https://www.intel.com/content/www/us/en/homepage.html) and AMD Home Page (https://www.amd.com/en).