If you've just started Skyrim and you're staring at that constellation menu wondering where your hard-earned perk points should go, take a breath. The good news is that Skyrim is generous. You'll have more perks by the end than most builds can spend, and almost nothing is unrecoverable. The bad news is that your first twenty or so perks are when a bad spread hurts most, because you're underleveled, undergeared, and a single mistake means a few hours of feeling weak. So let's talk about where the early points actually earn their keep.
The trees that are good on basically every character
Some perks pay off no matter what you're building, so I'd anchor your first investments here.
The single best early pick for almost everyone is the first rank of whatever armor tree you're wearing, Juggernaut in Heavy Armor or Agile Defender in Light Armor. That first rank alone is a flat 20% boost to your armor rating, and it scales as you add ranks. Survivability early is mostly about not getting one-shot by a bandit chief, and armor perks plus smithing do that better than anything else.
Speaking of which, Smithing is the closest thing to a universal "yes." Improving your own gear at a grindstone or workbench is gated behind those perks, and the difference between unperked and perked tempering is enormous. You don't need the whole tree. Grab Steel Smithing and then beeline toward whatever material your armor uses.
The third anchor is one combat tree you'll actually use. Pick your weapon and commit. One-Handed's Armsman and Archery's Overdraw both just multiply your damage, full stop. Don't spread three points across One-Handed, Two-Handed, and Archery "to keep options open". You'll be mediocre at all three. Skyrim rewards specializing early and dabbling later.
The trap trees (or trap perks)
Now the stuff I'd steer a new player away from for those first twenty points.
Pickpocket is the classic trap. It levels slowly, the perks are situational, and the gold-to-payoff ratio is terrible for a starting character. Same energy with the deeper Speech perks. Persuasion and the rest are nice quality-of-life, but they're not making you stronger in a fight, and early on you want power.
Block deserves a caveat rather than a ban. It's genuinely strong on a sword-and-board or two-hander, but only after you've got the basics covered. Sinking early points into Block before you have damage or armor makes fights drag without making you safer.
The biggest "trap" is subtler than any single tree: it's over-investing in a skill you're not actually using to level up. Perks are tied to character level, and your character level comes from raising skills. If you dump points into a tree you barely touch in play, you've spent a perk and you're not even gaining XP toward the next one. Spend where you're already swinging, sneaking, or casting.
A quick word on Enchanting and Alchemy: both are fantastic and a little dangerous. They're force multipliers, not early survival tools, and the famous fortify-restoration and crafting loops can trivialize the whole game if you lean in. Powerful, sure. Just know that going deep early changes the difficulty curve more than you might want on a first run.
A rough first-twenty roadmap
If you want a concrete plan: two or three ranks in your weapon tree, the first rank or two of your armor tree, three to four in Smithing, and then start filling in whatever your actual playstyle is leaning toward. Sneak if you're an archer, Destruction or Restoration if you're casting, Block if you're tanking. That leaves you flexible without ever feeling weak.
The constellation menu makes everything look permanent, but you're swimming in perks by level 40. Get the fundamentals down first, branch out once you can survive a dragon landing on your head.
If you want to read other people's level-one starts, the character builds tag is a decent rabbit hole.
So here's my actual question: which perk do you regret taking on every single run. The one you keep grabbing out of habit and immediately wish you hadn't?