It's possible that this
is a telephone conversation of course...
These corrections should be mostly good, but I'm not a native speaker so be a little cautious.
[] = optional addition
(×) = deleted but not replaced by anything
Yesterday, I went to Sara’s house. Kinoo Sara no o-uchi e ikimashita.
- Or "ie" instead of "o-uchi". (I wonder about "e" vs "ni" here and at the end with "shigoto e"... I think this is okay though)
She was cleaning her kitchen, but now she is cleaning her bathroom. Kitchen no sooji o shite imashita kedo, ima ofuro no sooji o shite imasu.
She is cleaning while listening to music. sooji o (×suru)shinagara ongaku o kiite imasu.
She also went to Yokohama yesterday. Kinoo mo Yokohama e ikimashita.
- Good Japanese, but it means something different to the English. The Japanese implies she goes to Yokohama a lot. The English just says that going to Yokohama was yet another of the things she did yesterday. I'm not sure which you intended so I'll leave it as is
She ate dinner there with Jason. Jason to [issho ni] bangohan o tabemashita.
- Unless she physically used Jason to eat the food you want "to" xD
How was it? Dou deshita?
- I'm not sure your original Japanese sentence works unless directed at Sara...
She said it was very delicious. Totemo oishikatta soo desu.
The food was perfect. Tabemono wa hodo ii deshita.
- I can't offer much help here. I'm not sure about "hodo ii", but I'm not confident that "kanpeki" works here either. Sorry ._.;
No, it wasn’t that expensive. Iie, sonnani takaku arimasen deshita.
- Missing line above? I guess I'll just assume we're not hearing all parts of one side of the conversation.
Will she go to Yokohama today? Kyoo mo Yokohama e iku no deshoo ka.
No she won’t go because it is raining. Iie, ame ga futte imasu kara ikimasen.
- Watch out for getting the halves the wrong way around with "kara".
She will probably go tomorrow. Ashita wa tabun ikimasu.
Maybe I’ll go too. Watashi mo ikimasu ka na.
- It might be just me but "moshika shitara" sounds to me like it's up to fate (not her choice / others' choices) whether she goes or not... Also, who's saying this line? Is it the main speaker or the person she's talking to?
It looks like fun. Tanoshisoo desu.
Do you want to come, too? [-san wa] ikitai n desu ka?"
- Avoid anata if you know their name. Also, you can use -tai form to ask about/confirm the wants of others. Also, this is just asking about whether the person "wants" to go; it's not an invite as such.
Tomorrow is no good. Ashita wa dame desu [ne]. /
Ashita wa chotto [muzukashii desu ne]...
- I'm a little confused here. Your original Japanese was a question (which doesn't line up with the English), and why is this person saying "tomorrow is no good" after saying "maybe I'll go too [tomorrow]"? ... If it was the main speaker who originally said "maybe I'll go too", then the translation for the "do you want to come?" line will have to change a little, because you can only say "ikitai n desu ka?" if they've already hinted that they want to go.
What about Saturday? Dooyoubi wa doo desu ka.
- Seems like you have a little weakness with wa/ga.
Okay, Saturday is good. (×Ee, )dooyoubi wa [tsugoo ga / choodo] ii desu.
- "Ee" seems wrong... you can't answer a "how" question with "yes", so... I'm not sure what to put there instead, though. Also I'm a little worried about answering with "ii desu" because sometimes it can mean "I'm fine (thanks)", but I think it's good here. I included a couple of ways to clarify just in case.
Well, I’m going to work now. Jaa, ima shigoto e ikimasu [kara].
- (There's actually a verb for "go to work", "shukkin suru".)
I’ll talk to you later! Jaa mata ne!
______________________________________________________(end of corrections)
You might want to clarify the middle bit about coming to Yokohama together.
The translation's pretty context-dependent there, and it's easy to get wrong.
Anyway, seems like you're doing well

Keep it up
