Now it's only $2000, can I mention 25,000 or more, and what do I need to do?

It has been two weeks since depositing, there is still some cash in the account, so why is the withdrawable amount 0?

At the time of the purchase operation, you must enter the amount calculated for the purchase of the stock, with a minimum of 1
Can I deposit funds to buy stocks?
Like if I bought $5000 from Amazon, it's a 1.x share