Think you will find getting a visa more challenging than others have indicated. Given you are from Yemen there is a high risk of you claiming asylum. Not clear if you are working and what form of resident permit you have in Saudi but since you don't have permanent residence in Saudi so not very strong ties. You need to show you can pay for your trip not your host. In this case your father is supporting the visit not you. You are visiting friends and not family so the purpose of the visit is not as strong. Not sure if you have travelled to other countries like UK, US, etc. but that would be helpful. Just warning you that your application has a high likelihood of being refused.