Tip, don't bother with the Anime of Deen.
Just read the original VN, watch Zero afterwards, then play Fate//Extra(AVOID the Anime) and drop the franchise afterwards. If you really want, you can do the UBW Series and Heaven Feels films afterwards, but I honestly recommend starting with the VN, as it has a much better structured entrypoint, with the story slowly unraveling over the routes. Then Fate//Hollow Ataraxia. I guess the Prism Ilya Series is also good, but other than that, the Franchise doesn't have much quality left.
And I guess Fate/Strange Fake
Also watch Zero after Stay night, as, while it is a prequel, it is heavily written to be consumed thereafter, as it spoils quite a lot of plotpoints that are intended to be surprising.
Avoid Deens adaptation, Fate Apocrypha(Has some great characters, yet is a pretty terrible story centered around the weakest-written of them) Fate Grand Order(Though the Manga Adaptation is at least decent, clear away from that gacha game for your own good)