Bismihi ta'ala 

Based on the common tradition narrated from Imam Muhammad al-Baqir (a.s.), when asked about the meaning of Surah Qaaf, verse, 15, he (a.s.) replied that there were Adams before and there will be Adams after. However, we do not have any further information beyond this. Nothing has been said in description of them.

The Almighty says in the Holy Quran:

وَيَخْلُقُ مَا لَا تَعْلَمُونَ

"And He creates what you do not know." (Surah al-Nahl, verse 8).

And Allah knows best.

This is a good question. As a wise scholar once said, it is likely that, in the Qur'an, Allah focuses on angels and jinn as the main sentient creatures other than humans since they are the ones we are most likely to have some sort of interaction with. However, this does not preclude the possibility (or, indeed, likelihood) of the creation of other beings. 

Bismihi ta'ala 

Like any relationship, we need to put effort and invest in our relationship with Almighty God. We must try as much as we can to build and strengthen this relationship.

Almighty God is always with us, but we have to make sure that we are doing our end in getting closer to Him.

Bismihi ta'ala

The best place to get to know about Almighty God is the holy Quran, which is the everlasting miracle of Islam and are the words of God. 

Furthermore, it would be recommended that you look into theological discussions regarding the metaphysical and matters related to God, like proving His existence, understanding His attributes, and other mind stimulating topics that would make you more familiar with your Creator.

Bismihi ta'ala

Imam Husain (a.s.), the grandson of the Prophet of Islam (s.a.w.) was beseiged in the plains of Karbala, Iraq, and innocently killed along with some of his family members and companions. 

Should you wish to read further about this topic, please refer to these following links:

https://www.al-islam.org/library/imam-al-husayn-and-karbala

And:

Bismihi ta'ala

The main purpose for attending places of worship is to worship, and not to mingle and mix with people of the other gender. This means that we need to keep the atmosphere in mosques and Islamic centres as spiritual as possible. With mixing between genders, this might lead to unwanted outcomes that would go against the ultimate purpose of places of worship. 

It is also a matter of convenience for both genders.