Hello,
i use lp 5.0.9 and sponge 7.1.8

When i try to connect to the server, i have [LP] A database error occurred whilst loading permissions data. Please try again later. If you are a server admin, please check the console for any errors. as error. commands doesn't work in the console.

It's a fresh installed server, i touched at nothing

Did you check the console for error (messages)...?
And it so, what are they?

https://github.com/lucko/LuckPerms/wiki/Storage-system-errors

fixed when resetting the luckperms file

Errors from the console : https://hastebin.com/isahuretuk.md

it seems that lp partially load. Could it be a spongeforge error?

The error already mentions a database error.
Please check the link Luck provided.

And how does i fix it, please?

I checked the link but i doesn't find any error that could match. where it is?