Hey sorry if it wasn't clear enough. There's 2 primary weapons you can unlock. If you click on the middle of the "no primary" sign you can click to the right to focus a purchasable item, click its box to buy it and click again to equip it.
Addressing your other points:
- Melee combat is planned but what form it'll take hasn't been worked out yet.
- Strafing is OP right now because the AI doesn't have any tracking or spacing logic to their attacks, redoing their AI is next on the list after fixing any bugs people find in the demo.