You just know some bard, not naming names, has probably written a song about how "you can cast Mending all you want / but you can't Mend my broken heart"
@Mithical Quick advice: If you want to be good with animals, you should opt for the "animal handling" skill. And also, swap the numbers for "Intelligence" and "Wisdom", so that wisdom is one higher than intelligence- rangers use their Wisdom stat for spellcasting
Basically, saves are used for reacting to traps, certain spells, and some effects. So you might make a save to do a last-minute dodge from some dragonfire, for example.
Box #1: Weapon Name. Box #2: Weapon Modifier. Daggers use Dexterity, so it's your Dex mod + 2 since you are proficient. Box #3: Weapon damage dice + appropriate modifier. (No proficiency.)
The weapon also has a damage type, i.e. slashing, bludgeoning, or piercing. I think daggers are piercing.
(on an unrelated note, are you using the form fillable PDF version of the character sheet? once you are finished you will have to select "Print" and -> Export to PDF, which unfortunately makes it non-editable but preserves the boxes.)
