Is it safe to store user's secure pass-code in database with encrypted form while creating bitcoin wallet?
Best practise is to only store a hash of a password, not the password itself. You should also include a random salt before hashing. You should be aware of which well-known hashing algorithms are no longer considered safe for this use.

Encrypting the password before storing it is not a good strategy because you end up with one encryption key, stored somewhere as plain-text, that can unlock all user's passwords. This is a gift to hackers.

You need to take care of how you hold the password in memory for use when encrypting and decrypting other data (keys etc). For example, you need to be sure other processes and plugins can't see into your processes' memory space and that before being released, any allocated memory is cleared. This should be automatic with most modern systems but it is your responsibility to be certain of this.

Yes, amateur attempting to write security code is probably a good way to destroy your business, destroy your reputation and put yourself in the way of civil or criminal proceedings for negligence.

To be honest this question might be better asked on somewhere like Security.stackexchange. There's nothing Bitcoin-specific about this.