I have not gone anywhere in a hundred years. A friend of mine lives in Georgia now. I would really love to visit him, and I have never been to Georgia. Like most countries, to be honest. Where do I start? I want to prepare everything in advance.

Well I will not tell you about buying tickets and also about booking a place to stay if you are not staying at your friend’s place. But I definitely want to mention insurance. It does not matter if you are going on a hike in the mountains or just visiting a friend, you need insurance. Specifically about Georgia I recommend this article https://www.dreamandtravel.com/buy-georgia-visitors-travel-insurance . There are great tips here, general recommendations and insurance requirements. I think this info will already be enough.