I am just curious why there is nothing to protect from magical spells other than spells. For example an armor or some shield.
Such a thing does exist in-canon
‘You wouldn’t believe how many people, even people who work at the Ministry, can’t do a decent Shield Charm,’ said George. ‘Course, they didn’t have you teaching them, Harry.’ ‘That’s right … well, we thought Shield Hats were a bit of a laugh. You know, challenge your mate to jinx you while wearing it and watch his face when the jinx just bounces off. But the Ministry bought five hundred for all its support staff! And we’re still getting massive orders!’
‘So we’ve expanded into a range of Shield Cloaks, Shield Gloves …’
‘… I mean, they wouldn’t help much against the Unforgivable Curses, but for minor to moderate hexes or jinxes …’
Harry Potter and the Half-Blood Prince : Draco's Detour
What's baffling is why no-one thought of this before. We can presumably chalk that one up to the relative safety of the Wizarding World for hundreds of years.
On a lesser note, people routinely use dragon-hide gloves to handle magical potions, their skin being notoriously resistant to many forms of magic.
One pair of protective gloves (dragon hide or similar)
Harry Potter and the Philosopher's Stone : Diagon Alley
In Chapter Thirty-six of Order of the Phoenix Voldemort indeed uses a shield that deflects spells:
Dumbledore flicked his own wand. The force of the spell that emanated from it was such that Harry, though shielded by his stone guard, felt his hair stand on end as it passed, and this time Voldemort was forced to conjure a shining silver shield out of thin air to deflect it. The spell, whatever it was, caused no visible damage to the shield, though a deep, gonglike note reverberated from it, an oddly chilling sound...