Painful memories of the last time I played this. The exhaustive wiki which I highly recommend.
From what I can gather, you’re playing on Peaceful level. This is good. Peaceful is your friend. I know everyone here’s raring for you to go balls to the wall on Normal, but trust me, the best way to get things done is to not die every 15 seconds. Worked fine for me.
The only problem, which you’ll learn once you get serious about the crafting aspect, is that not everything is obtainable from mines, plants, or harmless beasties. Even something as simple as string (required for bows and various devices) can only be had from spiders, which only come out at night on Easy (remembering that “Easy” in a video game is “Probably Won’t Kill You, But Update Your Will Just In Case” in most other recreational activities) or harder. And fighting enemies at night is when the fun really begins! 
“The fun” - Scenario 1
- A
rampaging thermonuclear apocalyptic humanity slaughtering goddess of absolute global annihilation “witch” shows up.
- She throws a potion at you.
- You die in five seconds.
- Maybe eight. It’s been a while.
“The fun” - Scenario 2
- You get spotted by one of those zombies that reduces your food level, and if you’re shaking your head at the very concept of that, buckle up.
- You struggle horribly to both gorge every scrap of food in your inventory and fight it and the other hunger zombies that show up, kind of like the most messed up Pac-Man ripoff ever.
- This continues until you either lose the struggle and die or Scenario 1 happens.
“The fun” - Scenario 3
- You get hounded by second-tier killers… skeleton archers, creepers, Endermen, the aforementioned spiders, etc.
- Man, are they supposed to hit that hard?
- Keep at it until you’re dead or Scenario 1 or 2 pans out.
You’re thinking of tackling the Nether. It has stuff like ghasts and blazes. It is worse than overland at night. I died repeatedly every time I was in the Nether. On the PS3 version… the only one I didn’t royally despise… I made extensive preparations for the Nether and still got whacked dozens of times.
See, the thing you need to understand about any long-running video game, especially in the age of live service and always-online, is that the programming staff is constantly trying to tip the scales of power against the player. (I noted in this journal how Ubisoft first put a +51 floor on all area levels, then reduced power-up sockets, then made certain attacks less effective… and on… and on… and on… and on…
) The usual step is to “nerf” anything that’s overpowered. In the case of Minecraft, however, the player has the power to alter the environment itself, and there’s no way to take that away without completely wrecking the whole point of the game. So the team worked the other end. Tougher enemies. More aggravating enemies. Deadlier enemies. Most hostile biomes. And if that’s not enough, make them even harder… and even harder… and even harder. Oh, and don’t overlook the little things, either. Carrots are convenient and perfectly fine raw? OP! Release swarming bunnies to gobble them! That’ll show ya! Cobblestone is everywhere and useful for a lot of things! OP! Put in a bunch of other mineral types which can’t be used for anything and do nothing but wear out tools! You can just grow a tree anywhere? Let’s see you deal with five tree types clogging your inventory, wiseguy!
This has been accepted standard procedure for many years, incidentally, so don’t expect any sympathy the first time you dip a toe into Survival Easy (or Survival Normal/Hard, which, if I’m being brutally honest, probably amounts to the same) and get blasted 50 ways from Jupiter. Well, okay, I’ll sympathize, but that probably won’t help very much.
But if you can build with the speed and precision of a Rampart TAS, you should be okay.
Anyway… my advice is to explore the Nether in Peaceful with flying on, explore the place a bit, and decide is this is the kind place you want explore with no flying and no unlimited health and also lots of fire-shooting monstrosities roaming about.
You seem to be doing fine so far, though, so way to go. 