I want to focus on your message you submitted with your homework first!

I know i need more practice but please Critique.

Try not to worry about this! The instructor 'Uncomfortable' provides some insight into this through the lessons. I would recommend reviewing the videos through Lesson 0 as most of the content in there has been very helpful to me, specifically I would refer to the section "Failure is a beginner's Job" Throughout this course, we will be failing, and this is very important to understand.

Should i draw in a upright posture ?

You should draw in whichever way is the most comfortable to you to make confident lines. Posture is important in the long run, so that's good that you are thinking about it. Good posture is going to help you draw for longer without aches and fatigue, however, it is up to you if you think keeping good posture is more important than being in a position that makes it easier for you to make a confident line. - I think Lesson 0 or somewhere in the beginning of Lesson 1 Uncomfortable also covers some information about better posture, how high your arms should be to make sure that you are able to make full use of the motion of the shoulder. So maybe it would help to go back and review the written and video content of these courses.

I try to draw simple things from real life

Drawing from life is good, but this isn't part of the assignment, I wouldn't recommend putting drawings in the homework submission. For drawabox focus on the exercises. If you did this real life drawing as part of your 50% to just draw for the sake of drawing, good job! But you may have missed the point of the 50% rule. So I would recommend again, going back through Lesson 0 to help you better understand what Uncomfortable means by that. You can also join the community discord if you have additional questions or are confused.

Okay, onto your Exercise sheets.

Superimposed lines:

The coursework suggests 2 sheets of super imposed lines, try not to worry about doing more, and only submit the 2 that are required. Uncomfortable speaks about this in the lesson content, so I would suggest watching the video and reviewing the text again if you are unsure why.

Your lines are good! Make sure your starting point of the line does not fray. This spot should be mostly accurate because you can take as much time as you need to make sure you set your pen down where the line needs to start.

Ghosted Lines:

This looks good! You followed the instructions of the exercise well.

Ghosted Planes:

It looks like you might be a bit more hesitant in these, there is a bit more wobble, remember to keep the motion of your line strong and confident! Otherwise great work still.

Table of Elipses:

Well done on the first sheet, you followed the instructions well.

On your second sheet of Tables you have elipses inside of your other elipses. Uncomfortable explains why this is not recommended in the course content, make sure to review that lesson text and video again to make sure you understand why.

Elipses in Planes:

These look good, looks like there is still some wobble and hesitation in your lines. Make sure you are rotating your paper to make each line as comfortable as you can. The elipses are good, I can see you are aiming to have the edges of the elipses touch the borders of the planes

Funnels:

Looks good, you followed the coursework and are checking your minor axis as well.

Plotted Perspective:

Straightforward, you followed the coursework, looks clean and well done.

Rough Perspective, Rotated boxes, and Organic Perspective:

I group this together because I have the same advice for each. You seem to start sketching over the same lines. Remember to only draw your line once and move on to the next, it doesn't matter if it failed, if it was inaccurate or it doesn't look the way you wanted to. Move on to the next line.

Otherwise I think these all look pretty good!