Right now, it is 7 pm at.m. on the weekend.

I'’ve already donefinished today'’s English study and, so now I can do whatever I want to do.

At fFirst, I'’m going to take a bath, and then I will paint some pictures.

This sets memakes me feel free!

Right now, it is 7 pm aton the weekend.

When you're starting a sentence with a time, add a comma after that time (ex: "after I went to the store," "at midnight," "when I was younger,") not sure if this is too helpful sorry
"On the weekend" is the correct phrasing, also is used for "on the [day]" but I'm not sure if you already knew that

I've already done today'smy English study for today, and I can do what I want to do.

"Today's English study" sounds unnatural
"I can do what I want to do" is correct enough not for me to change, but to make it sound better you could change it to "I'm free to do what I want" or "I can do what I want" (I recommend this one less)

At fFirstly, I'm going/I will to take a bath, and then I will paint some pictures.

"At first" talks about a past event

This sets meI feel so free!

To me, "this sets me free" doesn't sound like the correct phrase to use if you're referring to the activities in the previous sentence. "This sets me free" would probably refer to you finishing your work, which was mentioned earlier and doesn't seem like a proper conclusion if you put it here. My interpretation was that you felt free to do what you wanted, so that's why I changed it to "I feel so free."

Right now it is 7 pm aton the weekend.

I've already done today's English study andso now I can do what I want (to do).

At fFirst, I'm going to take a bath, and then I will paint some pictures.

What time is it?

*Option to capitalize titles

Right now it is 7 pm atin the weekend.

*to me "in the weekend" seems more natural. But check others as well.

I've already done today's English study andies so now I can do what I want to do.

Better :"so now" meaning therefore you have time to do what you want.

At fFirst, I'm going to take a bath, and then I will paint some pictures.

It seems ok to me.
Other words possible:
"First and foremost,... "
"So first,...
"Firstly, ...

This sets me free!

Ok to me.

Right now, it is 7 pm at the weekend.

I've already done today'smy English study andfor today and now, I can do whatever I want to do.

At first, I'm going to take a bath, and then I will paint some pictures.