There are two types of spells: strategic (world map), and tactical (battle). Both sets can be accessed by clicking the little book icon next to your mana bar. You can select spells and get information about them, and double clicking (or clicking the big Cast button) will allow you to cast the spell.

I'm not sure about this specific token, but Summons are generally Strategic spells and need to be cast on the world map. If you have it in your inventory, it should show up on the items list in the "Vitals" tab (to the right of the portrait). There's a yellow bar in the top right of that section that contains usable items that character is carrying. It will not display equipment.

If you have a unit inside your zone of influence, you can click on the Actions tab (next to Vitals), and there will be an icon that will take you to the shop. Note that normal trained troops can carry stuff, but they can't equip it - only Sovereign and heroes can equip items.

You should always start next to a Fertile Land tile. Start your first city next to it, then select it and click the Build button (hammer and a green building grid icon). This will build a farm on it and tie it to the nearest city. Farms produce food, which is needed to build houses so that the population increases and the city levels up. There are other resources on the world map, and you use them the same way - select and click Build. Note that they have to be in your zone of influence, and the resources are sent to the closest city.

I can't attest to the changes in the Campaign from 1.05, but they were supposed to put a lot more tutorial information, including shopping, food, basic city stuff. If you haven't looked yet, it should be worth exploring the campaign a bit.

If you select a spell that you can cast, the button should be green and clicking it once should close the spellbook and give you a targeting cursor - the tiles it can be cast on are highlighted green, and red is for tiles that can't be the spell target.

Going from memory (yay posting at work), from left to right: Gold income, arcane/tech knowledge income (should show both?), prestige income (the goblet), and available building space.

AFAIK, Protect Settlement has a max range so you need to be close to the city to cast it. It is an Enchantment, so if you cast it successfully you should see a new tab called Enchantments on your Sovereign (next to Vitals/Actions) that will show all the permanent spells he's maintaining.