Great job! You really shouldn’t be stressing too much about being able to write perfectly yourself at this stage though. Think of it like this, N5-N3 is all about understanding Japanese through active learning, and after that point, immersion will be more effective to learn new things, with other resources to supplement your learning of course. Through immersion, grammar will become second-nature. (Take this with a grain of salt, I’m almost done with N5 grammar, but I learned English through immersion too.) Also, my idiot brain tells me that your sentence kinda implies an order since you finish with making dinner, so if that was what you were going for, from my limited understanding, the て would also be a good choice, as in:
今日はそうじして、文法をべんきょうして、ばんごはんをつくった。(More like and then, or simply and, vs among other things)