I started the day as usual and ate a tiny chunkpiece of cinnamon roll,; a leftover from yesterday's party.

Could also say "my day" instead of "the day", but what you have is completely correct and natural too.

I suggested the semi-colon (;) instead of the comma (,) because otherwise you might be linking two independent clauses with a comma (which is often known as a comma splice).

The usage of "chunk" here typically implies a large or thicker piece, so having "tiny" before it contradicts this slightly. If you wanted to keep "chunk", then I would remove "tiny" as it sounds a bit unnatural.

I then started to work on my dress,. I pinned the fabric and then I basted it with red thread to the waist of my dress.

I also folded some clothes from yesterday, did some dishes and putturned my Roomba on to clean the floors.

You could also say "Turned on my Roomba to clean the floors" or "Set my Roomba to clean the floors".

I then started making the dough for the focaccia so my husband could eat it when he came back home at 19:00.

As you have not previously mentioned focaccia or focaccia dough, I wouldn't use "the".

I also texted my friend E. and she gave me a recipe to try and make apple pie crust, so I can try it next week.

Overall it was a nice day.

I would add a comma after "overall", (as "overall,") but it also makes sense without it.

I started the day as usual and ate a tiny chunk of cinnamon roll, a leftovers from yesterday's party.

I also folded some clothes from yesterday, did some dishes and puset my Roomba to clean the floors.

I also folded some clothes from yesterday, did some dishes and putturned on my Roomba to clean the floors.

I also texted my friend E. and she gave me a recipe to try and make for apple pie crust, so I can try it next week.