SNL's Black Jeopardy: What does "fid'na" mean?

fidna aka a-fixin' to African American Vernacular English

I fidna go to da stow

Translation: I am preparing to go the store. "Fittin' to" is commonly thought to be another form of the original "fixin' (fixing) to", and it is also heard as fitna, fidna, fixna, fin'to, and finsta UK essays

The immediate future marker finna. This feature is a contraction of «fixing to», which both blacks and whites use for the immediate future throughout the South: He finna go to work. This feature can be also reduced to the forms fidna and fitna

English, But Not Quite: Locating Linguistic Diversity
_{edited by Oriana Palusci}

Finna is a contraction of "fixing to"; though is also believed to show residual influence of late 16th century archaism "would fain (to)", that persisted until later in some rural dialects spoken in the Carolinas (near the Gullah region aka the lowcountry - Charleston S.C.). "Fittin' to" is commonly thought to be another form of the original "fixin' (fixing) to", and it is also heard as fitna, fidna, fixna, fin'to, and finsta. wikipedia

7 min video on Gullah and the Lowcountry

I don't know for sure, but I'd guess that the [d] in fid'na comes from the [s] in fixing to, the way that the [z] in isn't, wasn't or business can turn into [d] in some accents before the following [n] sound. Something like [ˈfɪksɪntə] > [ˈfɪksnə] > [ˈfɪsnə] > [ˈfɪznə] > [ˈfɪdnə].

If the intermediate pronunciations [ˈfɪsnə] and [ˈfɪznə] exist, that would support my guess.