Where?
You keep adding requirements, so more work is needed.
Multiple screens can't talk to each other.
TinyDB is easier than CloudDB for local storage, and you should be able to distinguish between the two and know where to use one and where to use the other.
what if now they are in same screen
All username and score information must be available before attempting to update it.
The screen Initialize event is a good place to ask for the latest high score list.
It should arrive before the user has a chance to enter his name and confirm.
do u have some kind of similar video for this, I'm lost (sorry I being so foolish ). Especially, I never learn the table.
See the introductory section.
Then see the nb191 add-ons for tables.
I added a new, simpler, tutorial for CloudDB top scores under a single tag.
tq i will try now 
i should create a independent database for username?
Tell us where "ttttttt" came from.
It is not a list.
Use the Companion and the Blocks Editor Do It facility to show the contents of that global scores table.
sorry, can i look the image of the Blocks Editor Do It
Without the Do It facility you are working with one eye tied behind your back.
https://ai2.appinventor.mit.edu/reference/other/testing.html
problem is use of the values one of this block (the operation > cannot accept the arguments ...) based on the error message.
You possibly can use DoIt to debug.
Use the MIT debugging advice Live Development, Testing and Debugging
and Enis's comments about the built-in DoIt debgger MIT App Inventor 2 Tips – TWO DOG APPS
There is a red X in your blocks image, in the gethighscores procedure.
That procedure is incompatible with storing scores and names in a table.
I advise removing that procedure.
You have fallen for the sunk cost fallacy, where you have devoted so much time and money into something that won't work, that you are reluctant to give it up.
I, for one, will not fall for that.
i save as copy and run with other projectId for cludDb, now it turn to this result ( show only 1 value, and keep replace it when it is higher than the existing value)
omg, i just got the 5 result !!!!(is my size of the listview problem i guess hahah)
may i ask how to adjust it to follow the ascending order
There is a reverse list block.
