Please be civil.

Assume I have little technical expertise. I have some games on the PC (lets say Dark Souls 2 / Walking Dead Telltale Definitive) that I’d like to play on the Steam Deck, where my saves do not carry over. What can I do to force this? Please do not use acronyms or vague terms, I need this explained like I’m 5. Thanks in advance, would really appreciate some guidance on this matter.

Is it complicated?