I am a female in my early 20’s and I wanted to ask that if there are no proposals coming through because I may not be that attractive and females are usually married for their looks, is there any dua I can read or anything I can do to help me get married, as I am aware that marriage completes half the deen.

Never put yourself down and be confident and trust in Allah that He will provide. Read ziyarat ashura for 40 consecutive nights and ask by the right of Ahl ul Bayt (as) to help you in this matter.

I have been committing a grave sin regularly and was unable to stop. I spoke to a local sheikh and they advised I get permanently married. I spoke to another sheikh who told me it would be almost impossible to stop sinning without marriage, but it has been years and I am still unmarried. They said muta was an option, but I strongly prefer permanent marriage. My parents are against the idea of doing muta and want me to have permanent wife instead.

Is there any advise you can give me? Is there anything else I can do to reduce sinning? I have tried fasting once per week and I make dua for marriage regularly. Is there maybe any other solution for this?

You could make a nazr (vow) that if you commit the sin then you have to do such and such for example fasting 3 days or give a certain amount of charity. Something difficult for you. This would defer you because when you want to commit the sin you will think of the things you have vowed to do if you make that sin.

I would like to ask you a question that I have heard a narration which says " whoever knows their self, knows their Lord". How to know the self?

When one learns about himself and the complexities of his creation he then recognizes that he has a Creator.

What is the permissibility of participating in Halloween, whether by giving out candy or taking ones children to receive it?

I would like to suggest that you take a look at the origins of this holiday.

It is permissible in islam to listen music where all the sounds made only by Human voice and hands (No instruments were used)?
https://youtu.be/emslA6Z69EQ
One of the example of music for which I am telling about.

https://www.sistani.org/english/qa/search/1329/

What are signs left to occur for zuhur e imam?

I would highly recommend this book for you

https://www.amazon.com/al-Mahdis-Reappearance-Sheikh-al-Din-al-Sagheer/dp/1976265231

Is it okay to ask for something or someone in the hereafter, if you are unable to get them in this world? In my case, it's marriage
I won't be able to marry the person I want in this world. Can I pray, that I get him in the hereafter?
To be more precise, we're together in the hereafter

There is no problem in that.

I have a question regarding najasah. If I eat at a restaurant with a kafir friend or family member, am Ii allowed to go back to that restaurant because now I know that a plate has become najis and spoon or dDoes it become tahir?

Yes it is fine to return there. The restaurants wash the plates before using them again.

Also we have a general rule that is to assume everything is pure until otherwise known that it has become impure.

What is the proper way of Salam?

السلام عليكم As-salaamu ‘alaykum

How can one help a sister that has decided to remove her hijab. How can one support her? I can understand it’s difficult, as I was the only person wearing a hijab within my family and I did not get such a good response at the beginning. I was blessed by Allah swt to follow the path of the Ahlulbayt(as) in 2015, I learned about Lady Zainab(as) and Lady Fatima (as). I started understanding the importance of the hijab.

Everyone has their own struggles they’re dealing with. Try to advise them the best you can. Let them know you are there for them and willing to help them if they need anything.