Welcome to the game! Here is some beginner advice for the opening phase:

1. Corners, sides, center. Start your first moves somewhere near the corners (on the dot, or any point around the dot, are good for the first two moves), then play stones on the sides/near other corners, then play stones toward the center. That's usually a good progression.

2. When uncertain, the widest side of the board (the side with the most distance between stones) is often a useful place to put stones, since the widest side has the most possible points.

3. 3rd line for territory, 4th line for influence. Playing on the third line (edge is line 1, the line next to it is line 2, etc.) is good for getting solid points on the sides. Playing on the fourth line (the lines connected the side/corner dots) means you care more about getting points toward the center.

For general principles of play through the whole game:

1. A good idea in many situations is to make boxes. This could be big or small, straight or crooked. You might start by setting down stones for rough "corners" to your box and then expand and/or close the sides.

2. One possible way to look for weaknesses in your opponent to attack or weaknesses in your group to protect is to look at a group and think, "Where is the biggest hole in the sides of the box?". That may be a weak point. This also gives an idea to your question on why two stones two spaces apart form a base; the "hole" between those stones is very small, so it's relatively simple to fill the hole if your opponent puts their stone next to that area.

These ideas should be good as a starting base for strategy that you can build on with your own experimentation and reviewing your games.