Purchased apps kept if the Apple ID is being erased

Hello there!

So when I bought my newest iPad, for work, I decided to use the mail from work to sign in as Apple ID to make a difference between devices and I have just found out that the account I used will be erased from the system and there will be another generated for the next working period and continues to be like this.

how can I do not to lose all the apps I have purchased ????

might I just create a new account and set it as family share??

what will happen then when I need to update ?

will it be enough remembering the password??

thanks a lot in advance :)