Please capitalize where necessary: one of our favorite vacation apartments sitges perfect for friends seeking to enjoy the seaside.
A: One of our favorite vacation Apartments Sitges perfect for friends seeking to enjoy the seaside.

Please capitalize where necessary: the device has a standard memory slot (such as an sd or micro sd card slot) so that you can either extend the internal storage with affordable memory modules or you can retrieve data, such as photographs, easily from a memory card.
A: The device has a standard memory slot (such as an SD or micro SD card slot) so that you can either extend the internal storage with affordable memory modules or you can retrieve data, such as photographs, easily from a memory card.

Please capitalize where necessary: airshells protective packaging available to rent at selected airports.
A: Airshells protective packaging available to rent at selected airports.

Please capitalize where necessary: unit-converter.org - converter for density units like gram per cubic meter
A:
unit-converter.org - Converter for density units like gram per cubic meter