A Summary (Leviticus 23:37-38).
“These are the set feasts of Yahweh, which you shall proclaim to be holy convocations, to offer an offering made by fire to Yahweh, a whole burnt offering, and a grain offering, a sacrifice, and drink-offerings, each on its own day;
These then were the set feasts of Yahweh which were to be proclaimed as holy ‘getting-togethers' for the offering of offerings made by fire to Yahweh, including whole burnt offerings, grain offerings, sacrifices and drink-offerings each on its own day. The ‘sacrifices' were presumably the purification for sin offerings of the he-goats.
“Besides the sabbaths of Yahweh, and besides your gifts, and besides all your vows, and besides all your freewill-offerings, which you give to Yahweh.”
And this time and these offerings were offered to Yahweh on top of the regular Sabbaths, and their own freewill gifts, and all their vows, and all their freewill offerings which would provide the basis of the feasting. All these too would be given to Yahweh.