Once started, you'll be prompted with the Overview screen. As shown next in figure 5.4, the Overview shows your current balances, the amounts pending, and any recent transactions.
Figure 5.4 - Bitcoin Core's overview screen after first installed.
Before receiving any Bitcoin, you should be familiar with some basic preliminaries to help protect your Bitcoin wallet.
When first installed, your wallet will be stored unencrypted on the disk. Malicious software can access your wallet and steal the private keys. To protect your wallet, you'll need to encrypt it with a passphrase, or a long password.
By selecting Encrypt Wallet from the File menu, you will be prompted to enter a new password. After you set it, you can change it by selecting Change Password under the same menu.