Choosing the right guns and ammunition depends on a variety of factors, such as your intended use, budget, experience level, and personal preferences.
Here's a breakdown of how to approach selecting both:

1. Determine Your Purpose - What are you needing them for?
Self-defense: If you're purchasing a firearm for self-defense, you'll want something that's easy to use, reliable, and portable. Handguns are often preferred for self-defense. Ammunition for self-defense, hollow point ammunition is commonly recommended, as it expands upon impact, reducing the risk of over-penetration.

Home defense: A home defense weapon should be easy to handle and effective at close range. Shotguns (12-gauge) or handguns are popular choices.
Ammunition for shotguns, 00 buckshot is widely used. For handguns, a defensive load like a +P hollow point is common.

Hunting: Your choice of firearm and ammo will depend on the type of game you're hunting. Rifles are usually used for larger game (e.g., deer, elk), while shotguns or handguns can be used for smaller game. Ammunition for different calibers and bullet types (soft-point, ballistic tip) are used depending on the game you're after.

Sport shooting / Target practice: This generally requires a gun that's affordable to shoot and easy to maintain. Rifles like AR-15s or handguns like 9mm pistols are popular for this use. Ammunition for 9mm, .22LR, and .223/5.56 are common choices.

2. Consider Gun Type
Handguns:Revolvers: Reliable, simple, and usually more accurate for beginners.
Semi-automatic pistols: More ammo capacity, faster reloading, and usually easier to shoot in quick succession.
Rifles:Bolt-action: Ideal for precision shooting and hunting.
Semi-automatic: Faster follow-up shots, used for tactical purposes or sport shooting.
AR-15: A popular choice for both home defense and sport shooting.
Shotguns:Pump-action: Simple, reliable, and great for home defense or hunting.
Semi-automatic: Faster follow-up shots, but more maintenance is required.

3. Choose the Right Ammunition

Make sure the ammuntion you choose is compatible with your firarm and also the correct option for the end use. 

4. Legal Considerations
Be sure to check your local laws on firearm ownership, and ensure you're following all necessary regulations.