I'm struggling to understand when and how I would use my spell save DC and my spell attack modifier.
Would I use my spell save DC as the DC that enemies need to beat when a spell calls for them to make a spell save?
An example of this is the spell burning hands. Since burning hands requires creatures to make a Dex saving throw and my spell save DC is 13, would they need to beat 13 to avoid damage?
As for spell attack modifier, I am completely at a loss on how to use that.
In the same way that a non-magic class would roll strength or dexterity to make an attack, a caster uses their primary casting ability to try and hit the target. Which stat you use depends on which class you play (the rule book tells you in your class section). The result is compared to the target's AC. If you equal or tie the AC value, you hit and the spell has whatever effect it describes.
If you cast a spell that requires a target to make a saving throw, the DC is what they need to roll (after adding their stat mod) to avoid or reduce the effect of the spell. Like rolling to hit, if their save equals or exceeds the value of your spell save DC, they pass and the spell's effect is reduced (often, a success will mean the target takes half damage instead of full damage).
A spell will either tell you to make a spell attack or direct your targets to make a [stat] saving throw. This is how you know whether you are rolling to hit the target or if the spell automatically "hits" but the target gets a chance to resist the effect.
