Perhaps this is something we can help you with @friendsfan367 - how to structure your story, where to start (past, present, future), and how to keep writing even with gaming glitches, reinstalls, etc.
When it comes to structure, I'd start with whether you want the story to be game-driven or story-driven. Game-driven allows the game to dictate direction, movement, flow, character development, etc. Play first, and write later. Story-driven is where you start with the story (a.k.a. the plot), you create pre-written background for characters outside of the game, you have an outline (typically, although some don't and there are pros and cons to having/not having an outline), and you write, and then go into game and set-up and screenshot.
Personally I do a mix of both. I like the game to flow and I'll direct my Sims to do things within the context of my story either straight, through cheats, or mods sometimes. I try not to pose because it's challenging and not always convenient. However, I have outlines, pre-written backstory, and character development I do outside of gaming in a OneNote or Word document and a post-it note system for my walls.
I think it's also important to come up with an overarching goal or purpose. Why are you writing? For purely entertainment purposes, to get your feet wet and/or stretch yourself as a writer, to get people thinking about a particular issue/idea/concept, etc. There are many, many more reasons.
You can also pick a challenge to give you some parameters like the legacy or another type of challenge. Sometimes this can give you focus and direction and give you a set of rules that are helpful when writing. Sometimes I find challenges to be too restrictive and I want to open up my story to more possibilities. This is precisely why the Colt Family follows a traitacy challenge (which isn't exactly like a legacy challenge in that it can continue past 10 generations if desired) and why Kass's story (KCKLF and KFLL) precisely does not follow a challenge.
When you have this goal in mind, this will help you structure your story and gameplay. Ask yourself what you want to accomplish with your story, what you want your characters to do or not do, do you want things to be random or planned in game, what type of story you're telling, and things like that.
When running into where to start, personally, I just start wherever the story takes me. I typically don't let the preset Sunday at 8AM (in TS3) define my gameplay and usually I have to do a little setup on the first day anyhow. Remember your overall goal.
For the Colt Family Traitacy, my goal is to tell Rachel Colt's story and to illustrate that she is ambitious (as this is the first generation trait I chose) and I do this through her work, family, home, friends, etc interaction. She also is an unofficial official member of the Racket family so I've been developing the Rackets a bit too.
My second goal was to try and be a little unique than the stereotypical legacy so I chose a traitacy (which is basically you follow legacy-like rules, and in my case, this means loosely, and you pick a trait to highlight for that particular generation, and the following generation, which I haven't gotten to yet, must have that trait, but highlight a new trait, and you repeat this for the third gen and so on, working through EA traits).
Then I chose to start her as a YA (which isn't terribly original), and to start on Tumblr with minimal backstory. I have since moved over to WordPress, and I'll probably explore back story a bit more in the future. I also chose to start in winter (which I managed with cheats) because everyone starts in summer.
Then with these goals in mind, I created my character and started playing with specific mini-goals to highlight her ambition (i.e. work goals - getting a job in politics, relational goals - aligning herself with powerful and connected people to advance her ambition, and personal goals - illustrating how she is wrapped up in work and moving forward.
Kass's story is its own ball of wax and I can talk about that later as I'm already getting a little long winded.
The point is start with your goals and that should help you determine where to start. If past backstory is important and relevant, include it. If starting in the future, and telling "past" stuff in flashbacks (which can be really cool) is something that sounds interesting, though it could be more challenging, do it. If starting in the present makes the most sense chronologically, start there, and this is by far, the easiest, I think. You can also alternate between time periods if you'd like - start in present, include flashbacks, include premonitions/dreams/visions for the future, or hop ahead to the future and tell things about the past, etc.
Finally, gaming glitches are annoying and reinstalls are the worst. Don't be discouraged. The key is to keep writing anyway, and explain to your readers the troubles you're having. They'll understand. I've had corrupted lots before and had to switch to a new lot to tell my story, but you can still use it (i.e. in KCKLF, I used an earthquake to explain the move to a new lot). I've had to reinstall the game several times either due to corruption or my own stupidity (i.e. I deleted my version tag once by accident). It can be frustrating and time consuming, but keep going. The first thing I do is start up a new game with my characters (hopefully saved and if not, then I recreate them) and the lot (or I recreate the lot or move to a new one). Then I just pick back up where I left off although it requires some cheats/mods setup (i.e. like for relationship levels, careers, etc) but this helps my readers follow and I don't have to start from scratch.
These are just my opinions and some of the practices I use. I hope it was helpful, @friendsfan367 and let me know what other questions you have.
Thoughts, Reading Circle?