Randomly putting this out here. If you want to become married you go to Riften and speak to one of the priests who hangs out in either their Temple of Mara or the Bees in for the 'Amulet of Mara'
1)The priest himself explains how it works. Pretty much it's just getting a permanent (and free) companion that can make you sammichs on demand. There are also extra benefits like if they sell stuff they can give you a 'share' of their gold (I think they make profit whether they're following you or at their (or your) home, size depending on how frequent you ask. I think you also get a "lover's company" buff if you sleep with them around you. Imo you should just marry ones that can accompany you on journeys.
-Aela from the Companions in Whiterun is an example of a spouse that can give you gold regularly and is a kickass fighter. She hurts with a bow and can do considerable damage with her tiny dagger, which I think you can replace/
-Companions that accompany you in your journey, married or not, are always worth having around and really have saved me countless times in tight spots but drawing aggro first or by helping me fight hard 1v1 enemies.
-Also don't worry about any companions getting lost on your way to a place. All you need to do is fast travel or enter a new area and they spawn with you once you're done loading.
2) Also, this is personal preference, but I personally don't use horses. That 1k gold you spend is better off buying houses for storage (cheapest in 5k in Whiterun, I think) or getting 'training' to level up quicker and be more effective overall. If you go with the early main quest and learn the Sprint shout from the Greybeards, you can pretty much spam it to get around (especially if you have an Amulet of Talos that reduces the cooldown by 20%)
-If you really want a horse you can try this: Outside Riften is the local horse stable. I think it glitched but I challenged him to a brawl, won, and all his belongings changed status from 'steal' to 'take.' THAT included the horses in his stable.
3) There's a shit load of things you can do before continuing with the main quest. I've only finished training with the Graybeards and killed the dragon interrelated to the quest regarding training and I'm level 21/22 with my specialized skills (Archery, One/Two Handed, Block, Heavy Armour, etc) in the high 50s plus I found about 2 or 3 (disregarding the main quest ones) Dragon Shouts. That's about half way to the max, and I've played probably more or less 1% of the main quest and spent at least 25-30 hours with other things.
4) I wouldn't buy things from the merchant early level. I still haven't bought anything past lockpicks and potions (always worth the money) because if you just spend time exploring out in the field you can get a crap load of great loot exploring dungeons.
-If you can find one of the Dwarven mines you can get a crap load of Dwarven heavy armour, but you need to play safe. Bring a companion along.
-For light armour, In dungeons I've come across Elven armour which is one of the best early light armour you can get your hands on.
5) Always, always, always try to get a sneak bonus anywhere if you're the type that also levels up their Archery. In my opinion bows are much more viable than sneaking with a dagger when you're trying to assassinate weak enemies. There's a point where you can literally one-2 shot lower tier slumbering nord zombies and bandits before they could get up. Play enough and they're obvious to pick out which one is a zombie among the corpses in the Dungeon's Hall of Dead. Not only do you save ammo, you save time.
6) No matter what class you're going for, imo you should always look to pick every lock and keep your lock level high. There are a lot of rooms/chests in dungeons that are inaccessible without lockpicking and you miss out on a lot of loot. If you're worried about losing picks, just save right before.
-Note: I think locks reset their sweet spot every time you quit lock picking.
7) I know this may sound surprising but you can save DURING fights. I'm not even kidding about it. It's really damn useful to have a save when you're trying to clutch fight a giant or dragon that you can go back to and plan your next move every time you make a mistake and lose the fight.
8) On that note, don't try to fight giants early level. They one shot you into space.
-One thing I have to say though is that there are points in Skyrim where you can kite a giant (or equivalent) by luring them to one of the city watch towers (or equivalent) where they can't enter through the small doorway. At level 5 I lured two giants (and their mammoth) outside Whiterun to Whiterun's local watchtower and kited it at the doorway. That's also an easy way to get a mammoth tusk for one of the quests in Whiterun.
There's a lot more info I've amassed but I'll type in next time I'm not bored or busy not playing Skyrim.