Vanilla sauced is, as the name implies, a modpack that inspires to implement many changes to the base game without changing too much of it's core gameplay loop.
You will not find huge mods like Immersive egnieering in there, however, survival, tool and weapon making, armor and such has recieved tweaks and changes to make things a lot more interesting.

Here are some of the mods and the changes they bring:

Survival:
-Serene seaons, Legendary survival Overhaul, Hardcore torches, Map atlases, Let's do series, Farmer delight & addons, Cooking & farming for blockheads, Starcatcher, Sushi go crafting, Magnum torches:
These mods change how you will aproach living in the world, as now you have to worry about temperature and thrist.
Not to worry, new plants exist in cold and hot biomes to help insulate yourself, as well as tons of new food items to keep you hydrated, and even warm or cool you off.
Keep an eye on the calendar, as seasons changes, temperatures may rise or lower, making farming a lot harder.
Not to mention, vanilla torches and lanterns now have a limited burn time, with lanterns requiring refueling ever so often. Be careful, as nights are extremely dark... So don't forget to pack a extra torch, or better yet, find alternatives!
As such, campfires will be essencial, as they not only burn for long, but also provide health regen, and keeps mobs at bay. You might figure out later how to repell mobs alltogether with some large torches!
Oh, and orientating yourself will be primordial, so make sure to make a map atlas, with either some slime or honey bottle and paper. They aren't as powerful as other minimap/map mods, requiring even more empty maps to be able to display more and more, in exange, maps no longer require a compass to craft!

Weapons and armor:
-Overgeared, Spartan weapons and shields, Tetra, ewewukek's Musket mod, epic knights, Lucky's wardrobe, Clothing of the lowlands, Expanded combat, Just hammers, Ice and fire, Hexerei, Occultism:
These lands are not as safe as they once were, as such, you will need plenty of protection. If you think however of jumping into the first hole to get iron immediatly, I am afraid this will not work here.
The whole process to getting your first tools is going to be a bit more involved. Overgeared changes how basic and some modded weapons and tools are made, with the first task being to aquire some flint, use it on some stone to get pebbles, then but one in each of your hands to knap some stone tool heads.
This will unlock your stone tools, which you can in turn mine up to copper with. Once you got some, smelt it, make a smithing hammer and wooden tongs, heat some ingots again in a furnace, and voila! You will have some copper tier tools. The same logic will apply to iron and diamond, with some new steel equipement too!
If you prefer a more modular aproach, Tetra is not a bad place to look at. Once you make a tetra wooden hammer and use it on a crafting table, it will turn into a tetra table, allowing you to customise your tool to your hearts content, and you will recieve a sphere that will help you choose what material would work best for said equipement!
Do not forget to place tool racks above it to place the necessary tools to work on your projects, you will need a tool with cutting power, smithing power and axe power to work efficiently. Once you reach blackstone tier tools however, you will have to seek the old buildings deep in the earth, likely more in cold biomes, to find higher tier benches for even more powerful toolmaking.
And of course, if all else fails, just blast them with a musket, or smack them with gloves! Just try not to end up in a dragon's stomach!

Transportation:
-Horseshoes, Callable horses, Two players one horse, Railcraft reborn, Immersive aircraft, Paragliders, Grappling hooks reforged, Small ships, Walking canes, Traveler's boots:
With the new terrain, comes new challenges to overcome, as such, you might want to invest in some way to cross the large terrain faster, And boy do you have options!
With overhauled horses, a brand new set of trains, some gliders, grapples and planes, as well as large ships, exploring has never been more appealing!
Just make sure to look where you are driving or landing those eh?

Exploration:
Terralith, Dungeon Crawl, Bounties, Yung's addons, Goblin's Tyranny, Kobolds!, Goblin trader, Towers of the wild, Homestead:
The world is much more different now, with even villagers showing up in the middle of nowhere, some new races more or less friendly and open to trade, and even new places to explore and loot!
With brand new terrain, towers, biomes and dungeons, you will have plenty to seek forth and find riches. Just make sure you are properly equiped...

Logistics:
Tom's simple storage, Pipez, Item collectors, Storage drawers, Sophisticated backpacks & storage, Iron furnaces, Clayworks, Create and addons:
All this gathering is going to take quite a lot of space back home, fortunately, with a large backpack, and some brand new storage and processing options, you will be able to process, store and craft things much faster and easier!
And if you wish to automate, you can always start a town, who knows! You might attract some settlers who can help gather for you!

... And many many more mods not listed here! If you enjoy vanilla but want a little more spice, this pack might be what you waited for!