Orc Bastion is a bit hands-off with its tutorializing, so here's some info to help you get started.

Manual Saving (almost anywhere)

If you're not near enemies or in midair, you can usually save the game. There are no auto-saves, don't forget to save on the reg!

Quest Radar

The circle in the top-left corner of the screen directs you towards your goals (marked as ?), and there's a simple quest log in the menu. If no ? is visible, there are no story or side quest triggers available in the current area.

Exploration

While out and about, you can run, jump, swim in water and climb ladders and vines. Talk to NPCs in towns and check hidden corners for items. The world map itself has a lot of hidden items, as well. Watch out for that little twinkle. If you get too close to enemies, a battle will trigger. You can avoid their line of sight and hide behind walls or barrels if you wish to avoid battles. If enemies emit a faint red glow, they may be quite strong. You may want to save the game before attacking them.

Battles

Each enemy has weaknesses and resistances. Hit a weakness to delay an enemy's next turn a little. Hitting them from behind or from above works, too. For back attacks to work, you need to be at least one cell column to the left or to the right of an enemy. If you hit a weakness, your star meter (upper left) fills up. Once it's full, the next playable character gets two turns.

Learning Skills

You'll get new skills as you progress. To make use of them, they need to be learned. Not all characters can learn all skills. Enter a character's skill menu to see what skills are available. A skill marked with " ○ " is currently being learned and usable, and a skill marked with " ● " is fully learned and always available to use. To learn a skill, select it and set it to your "Learn" slot. During battles, you'll receive LP (Learning Points), and once you've met an equipped skill's point requirements, you can use it permanently, and equip the next skill to learn.

Using Skills and Items outside of Battle

You can use healing spells outisde of battle. Some of them can be cast on all player characters simultaneously. Do so from the context menu of a skill that's been learned or is currently in the "learn" slot. You can also use healing items and status upgrade items via their context menu (select an item in the "Items" menu, and the context menu appears to the right of them).

Sometimes, you need to use a skill on certain hotspots to progress. It needs to either be equipped in a "learn" slot or fully learned to be used. Select it in the skills menu of a character and pick "Use Here" to use it on hotspots. Hotspots are marked with "!" icons that grow bigger when you're near enough. An early quest requires you to melt an ice crystal with a fire spell, for example. Stand in front of it and select "Use Here" from an learned/equipped skill's context menu.

Masters make you Stronger & make more Skills available

While exploring, you'll come across masters who'll join you in Rok's Fort. The Wyrm Altar inside the fort gives you new skills as you find more masters to serve. Keep an eye out for these big fellas! Once you've served them (talk to them in the fort), you'll gain some stat boosts, as well. Your party members are also masters -- talk to them at certain bonfires if you wish to serve them.

Leveling & Buying Equipment

You'll have to keep somewhat up to date with your equipment and your levels. While the game lets you avoid most battles, you may end up under-levelled if you avoid fights too often. You'll need experience points from battles, as well as LP to learn skills. Shops let you buy and sell items. Selecting equipable items will show you how they'll affect a character's stats. You'll also find valuables during exploration, and you can sell them for some profit.