Help recognising 3.5" Touchscreen LCD and patching to Mega

You have a 3.3V module with a 34-pin header.

It should work just fine with a 3.3V Arduino like a Due.

If you want to use a 5V Mega2560, you will need to provide at least 21 level-shifters for the TFT.
And several extra level shifters for the Touch and SD.

AS far as I know, there are not any ready-made Adapter shields for the 34-pin header.

As long as you connect the correct pins with the correct 3.3V logic, the ILI9486 controller should work fine with UTFT, TFT_HX8357, (or MCUFRIEND_kbv with appropriate SPECIAL)

David.