Make sure to read through the information about the gift card. Often they will have regional restrictions, so a gift card purchased from one country may only be redeemable in that country
You might be able to specify the email address that it is sent to, in which case you can put down your recipient. However, it may just be sent to the email associated with your account on the retailer’s website. If this is the case, you can share the code with the recipient through email or text. The recipient will use the code to redeem their game on their Sony account.
Make sure to search for PS4 games or use this filter while shopping. Browse in different genres that you know they like. Look up the genres of other games you know they play or have shown an interest in, and then browse in those genres. You can also look for popular or new releases.
If you are having a hard time knowing what to get, consider asking someone who works at the store for their opinion. They can often provide suggestions based on age or interest in other games.
