Need to replace a receptacle closest to panel that has a light and another receptacle inline. All are aluminum. They have alumiconns on them (purple) pigtailed. Need to replace sink receptacle with GFI receptacle. The non-gfi receptacle has a white wire connected to the bottom left side and a black to the bottom right side. I think black goes to (line) top right gold on gfi and white to (load) bottom left silver screw. Is this correct? I live in florida, I am using a Leviton 15amp GFTRI-RKW gfi.
Almost everything in mains is done in hot-neutral pairs. GFCIs are no exception. LINE has 2 terminals, brass and silver, and is used by a hot/neutral pair - both black and white wires go to it. These would be your two pigtails.
LOAD is used not at all, unless you intend to use the particular feature it supports, and you know exactly what you're doing. That's why it has warning tape on it. You do not seem to know what that feature is, which is fine; simply don't use it.
Use an AFCI+GFCI breaker instead
Some people say install a GFCI breaker which protects the whole circuit. It's true, it'll be cheaper than GFCI receptacles at every socket or 4 alumiconns for doing it in this box. but think bigger.
Arc Fault protection (AFCI) is absolutely perfect for protecting aluminum wiring. It detects the thing that is most worrisome. AFCI has to be installed at the breaker because it protects the wires.
They make combination AFCI+GFCI breakers that cost only $10 more than a GFCI breaker. That is the thing to use.
So long as you only need GFCI at the one outlet, and not the rest, you can install a GFCI here on the pigtails, connecting to the LINE terminals (only) White (neutral) to Silver and Black (hot) to Brass. LOAD are not used.
You cannot GFCI protect the rest of the outlets that follow without (inferring from what you have written about "closest to panel" yet only having one set of pigtails) having the aluminum wires that are evidently all joined to one copper pigtail separated and re-joined to two copper pigtails, where one set would come from the panel (line) and the others would go on to the devices that follow (load.) Given that pigtailing copper to aluminum in a listed manner may be expensive to have done, probably cheaper to leave as is and use an additional GFCI if needed, or use a GFCI breaker to protect the whole circuit at the panel.
Gfci should be placed at the point power comes in,that will be the line on the gfci. Black brass, white silver,ground to ground green screw. Then load out feeds light, and other outlet, load out. Black brass ,white to silver, and ground to green screw. In the box should be stickers that go on plate,to the other outlet add sticker . Now you have gfci that also gfcis other outlet and light. May want to edit your question, a bit . If you only need that one outlet gfci, then hook up to the line side and only that will be gfci protected.