I wanna write something sort of like how the developers at bethesda did. I keep finding myself fascinated with how much they have wrote just for the lore and am wondering what can i do to start something like this? what would i have to do ? how far would i have to go? any help or ideas would be helpful!

Start small and build up. If you go back to TES: 1 days, there wasn't nearly the volume of lore that there is now. Same with other franchises such as Warcraft, etc... As games are released, more characters and stories are added to the volume of lore. If you try to plunge in an build something as large as the existing TES lore-base all at once, you're going to burn out long before it's finished.

Look at Tolkein, for example. He built a huge lorebase for Lord of the Rings, but he built it over the course of his lifetime.

Well i know it wont happen over five minutes i just am wondering where i should begin because thats kinda hard to figure out? Should i start with a timeline? or what?

I wouldn't start with a timeline. I would start with a world. Whenever I am crafting a new world for a game or story, I start with drawing a map. I begin with pure geography to start: mountains, swamps, plains, etc... After that, I'll start filling in the world with who lives where, why do they live there, etc.... Who is fighting with who, and why are they fighting? Things such as back history sort of naturally fall into place, and as I get a better handle on a specific race I can start to figure out what gods they worship (if any), who their heroes were and who their chief enemies are. And of course, there is always the purely fanciful things that just occur to me out of the blue: a particular fabled monster, for instance. I might have an idea for a fabled monster, and try to find some place in the world where it might belong. Of course, such a thing will then affect the people who dwell nearby, thus factoring that monster into local mythologies and lore.

It's an organic process of growth, just like any complex thing, built up from smaller inter-connected pieces.

Maybe a map and a timeline? Any good tips or ideas for helping me get started?

Also what about coming up with words? like names or country names or even days of the week or month? how would you go about with that and not make it sound really stupid?

Just grab a pencil or a wacom tablet and get started. The sooner you start getting stuff on paper, instead of just asking questions, the sooner you'll start learning the real things (things that can not be taught) about writing and world building.

Also what about coming up with words? like names or country names or even days of the week or month? how would you go about with that and not make it sound really stupid?

You can use a name generator or just make them up yourself. One thing that bethesda does often for city names it to take two words and push them together, i.e. Elder Root, Highrock, Hammerfell, Black Marsh, etc. For city names, think about the suffixes that they usually have(burgh, sted, hold, helm, mouth, and ford to name a few). As for naming months, I'd probably just wing it but you can try and pick apart what TES did for their month names.

How I usually start forging a world is I picture in my head what kind of world it will be, and then take a pencil and draw a first draft of a map. I'll work off of that for a while and then probably redraw the map with more/different/less cities, more interesting features, more natural transitions, etc. I generally figure out what I'm doing for races fairly early on as well.

After I have some basic nations with their conflicts, cities, setting, and gods, I'll usually start mapping out their more intricate lore(origin, heros, factions, etc).

I'd say you can pretty much do this however you want. If it helps you, make a timeline. I personally love geography and history, so for me making a map works pretty well.