Edit - after taking a moment to step back and look, I realized I was way overthinking the issue. If anyone in the future finds this, you’re also overthinking it. All you need to do is place block signals, facing in both directions, at the locations of the red lines in the updated image. This will mark the entire central line as a block, and prevent any trains from entering it until it is empty.

This is my first time messing with trains, and here’s what I’m trying to do:

I have two bases, and at each base, I have two stations. I have a single bidirectional track between the bases (Bad diagram attached). All I need is for one train to go from station A at base 1 to station A at base 2, and one train to go from station B at base 1 to station B at base 2. The timing is not important - I don’t care if they both wait 5 minutes before moving; I just want them to move.

I’ve been messing with path and block signals, and managed to get half a cycle to work, but now both trains say that signals are preventing them from moving.

I don’t know what I’m doing and I hate trains please help. And if you can do so without telling me I have to build a loop or something, that’d be great.