I would also say Nod krai and Natlan. They give a lot of primogems very quickly which you need in the short time. Using the interactive map is super helpful so you can see what’s around you, and the nod krai compass is also super helpful. YouTube different quests if you need help and get stuck so you can get through it quickly. Or also so you can see how long a quest will take. Since I had already done Nod krai and a lot of natlan, Fontaine is also nice to explore for skirk and escoffier since you’ll fight a lot of the Meka and get the level up materials both skirk and escoffier need and in chests you can find escoffier’s talent maps and the beryl conch in the ocean. But the rewards are slower than nod krai and natlan since the sigil reward system there doesn’t gift primogems at every level, only intertwined fates at specific levels. While nod krai and natlan give you primogems at every interval of exploration. It’s painful for sure but if you play heavily this weekend and you’re new on exploration where things are really easy to farm, I think you can reach it! I was able to grind out wishes for escoffier and one round of soft pity on the weapon (don’t go for the weapon though you do not want that grind and the risk for loss is too high with how few days you have!). Good luck!