Try to have a particular build in mind when deciding which stats to level up. Do you want a hulking brute who swings a giant club with reckless abandon? Pump points into strength, endurance, and vitality. Do you want a quick katana-wielding ninja? Dexterity is your best bet. Imagine the character you want to play as, and check out the kind of equipment you want to wear. Not all weapons and armor follow the same rules, but generally, heavy blunt stuff requires strength, light sharp weapons require dexterity, though both can be enchanted so they buff with your magic/faith stats (that's for if you're a magician who wants a decent weapon). Lances will be dexterity-based, but heavy lances are a mix of strength and dexterity.
If you're confused about stats and soft/hard caps look them up on the Dark Souls wikia page For example, you get dramatic boosts in health and stamina until you hit 20 in endurance and vigor. Past 20, which is the soft cap, health and stamina go up but as much. Past 40, the hard cap, the stat increases are too low to warrant pouring more points into. This isn't the same for all stats, so don't feel guilty about looking them up online. I mean, you can tell when there's a cap if you note how much your stats increase per level, but I can't imagine many people doing that.
As for battle technique, be conservative. If there's a sizable chunk of your health bar missing, do yourself a favor and hold back on attacking a boss or tough enemy until you heal. Unless you can kill that enemy in one or two shots, chances are you'll get hit and quite possibly die. Sometimes stupid chances will pay off, but more often than not, Dark Souls will punish you for taking them. Also, don't horde souls. If you have a large number (tens of thousands) ask yourself if that's something you're willing to part with. If you can level up multiple times, do yourself a favor and head back to Majula before taking on that boss/new area. It might take longer, but you'll be better prepared to face the challenges that lie in wait — with the added benefit of fewer souls to lose.
I could go on and on, but there are already guides out there detailing what you need to get yourself started. Otherwise, take a deep breath, be patient and don't fight with your back facing an area you haven't cleared of enemies yet. Good hunting.