First and foremost would be the FOUR basic rules of gun safety! However as far as advice & tips these would be some.
1. Owning guns is NOT all about self defense. Self defense use of guns CAN be an element of ownership but should NOT be a priority of or for ownership.
2. Determine what interests YOU with regard to guns. Do not be influenced by what you hear/see/think is the 'most popular' platform, style, make, model or design OR caliber.
3. Gun ownership can be demanding and takes time and responsibility and a monetary investment. Make sure it Is it something you want to take on as a 'dedicated' part of your life.
4. BEFORE making any decisions get with people you know who are current gun owners. Ask questions, maybe ask to be taken out when they go shooting to observe and maybe be allowed to shoot as well.
5. Last but not least BE CAREFUL of what you watch on YouTube (if this is something you do) with regard to ANY guns/shooting/2A YouTube sites. Some are very good and informative but MANY are very opinionated, one-sided and misleading. Some give information that can be legally questionable up to downright dangerous - as one YouTuber who is now in jail found out a year or so ago....
These are just a few but it's info & advice I believe is important to pass along.