From the comments:

"Receiving 10%

This means that 10% of the total supply (10% of 1B Luna tokens = 100M Luna tokens) would be split across everyone who holds Luna Classic at the time of the new Launch (2022.05.27 03:59:51+08:00).

This would likely be handed our on a pro-rated bases. You would receive whatever portion of the total Luna you hold.

If you hold 1% of all total Luna Classic, you would get 1% of that total 100M new luna tokens. There is alot of Luna in existence. So you would need to figure out how much you own of all tokens to figure out how much you would be airdropped.

I’ve excluded some example math at the bottom.

Vesting Period

A vesting period means that the total amount you would get in the above section is given to you over a certain period of time. What ‘10% unlocked at genesis, 90% vested over 2 years thereafter’ means is that:

At the time of launch, you would get 10% of the total amount you should receive based on the calculations above. Over the next 2 years, you will get the remaining amount.

Example Math

Lets say I own 10M Luna

Total Amount of Luna Classic in Circulation = 6.5 Trillion
Amount of Luna Classic I own = 10M
% of the total amount of all luna classic that I hold = 0.00154%

Total Amount of new Luna being airdropped to Luna Classic holders = 100M
Total Amount of new Luna that I would recieve = 100M * 0.00154% = 153 Luna

What would I get upfront = 15.3 Luna
What would I get over 2 years = 138.45 Luna"