Well I'm currently using a heavy armor one handed block and archery Breton and getting my ass handed
To me. What's a good combo like character wise and what skills to use for legendary cause I am gonna beat it on legendary and not at all lower difficulty.

Start smithing, maybe take some magic resistance.

Try to level up Restoration or alchemy and make health pots, nothing is more important then healing up all that dmg restless draugr is doing, another thing, Use a follower or conjuration or illusion, i think the difficulty may be impossible without someone to tank for you, of course this doesnt apply to the sneak/archery combo. its just easy mode if you wanna go that route.

maybe you should take a follower with you and spend a couple of time smithing, enchanting and doing potions, get good gear and go do bounties i know it sounds silly but it helps you to level up if you are low leveled and dont forget take a follower with you !

just boost off of Ralof in the intro. Leveling sneak by backstabbing him is by far the quickest method, I managed to get it to lvl 6 legendary (just get his head glitched into a rock so he can't detect you).
1 handed and 2 handed are a bit more difficult to lvl but still very doable, and that's about it.

If you however fancy high elves then you have a much wider field for leveling. Use fury to get him to attack you and additionally lvl your light and heavy armor, block, restoration, and illusion. You can easily leave helgen at lvl 30-50 with this method. It really helps if you just want to dive right into a legendary play through.