Factorio's UI provides vital information. The top-left displays your inventory and quickbar. The top-right shows your current research progress and objectives. The bottom-left is your chat and console. The bottom-right contains your map and minimap. Pay close attention to the quickbar for easy access to frequently used items.
Press E to open your inventory and crafting menu. The crafting menu allows you to see recipes and queue items for production. Familiarize yourself with the different tabs for raw materials, intermediates, and structures.