Salam Alaykum ya akhi.
Only Allah knows what will await the righteous believers in Paradise. There are some verses in the Qur'an which suggest that the people of Jannah and Jahannam can talk to each other (7:44, 7:50, and others).
I doubt that you would want to actually go to Jahannam, for whatever reason, once you are in Jannah (or indeed any time ever). Also the people therein are already suffering the perfect punishment by Allah, may He be exalted.
Praise be to Allah for granting you guidance and turning your heart towards His religion!
First of all, welcome to Islam.
>Any resources for newly converted muslims?
The most important pillar of Islam after the Shahada is the Salah (prayer). Here is a guide how to perform it: https://www.wikihow.com/Pray-in-Islam
Read Qur'an online: https://quran.com/
Read Hadiths online: https://sunnah.com/
Find prayer times, nearby mosques, Qibla (the direction of prayer) and more: https://muslimassistant.com/en
>Are drawing and music haram?
There are Hadiths which indicate that drawing pictures of animate beings, with details such as eyes, is forbidden and that angels do not enter a house in which such pictures are present.
>Narrated `Aisha: The Prophet (ﷺ) entered upon me while there was a curtain having pictures (of animals) in the house. His face got red with anger, and then he got hold of the curtain and tore it into pieces. The Prophet (ﷺ) said, "Such people as paint these pictures will receive the severest punishment on the Day of Resurrection." [Sahih al-Bukhari 6109]
>It was narrated that Abu Talhah said: "The Messenger of Allah (ﷺ) said: "The angels do not enter a house in which there is a dog or a picture." [Sunan an-Nasa'i 4282]
And there are Hadiths which indicate that musical instruments are forbidden.
>Narrated Abu 'Amir or Abu Malik Al-Ash'ari: that he heard the Prophet (ﷺ) saying, "From among my followers there will be some people who will consider illegal sexual intercourse, the wearing of silk, the drinking of alcoholic drinks and the use of musical instruments, as lawful. [Sahih al-Bukhari 5590]
>What are the main differences between sunni and shia?
The main difference is that the Ahl-us-Sunnah wal Jamaa'a (Sunni Muslims) recognize the legitimacy of the Four Rightly Guided Caliphs (Rashidun Caliphs), who were Abu Bakr, Omar ibn al Khattab, Uthman ibn Affan, and 'Ali (may Allah be pleased with them). These four were the closest companions of the Prophet (ﷺ) during his lifetime.
The Shiites claim that Abu Bakr, Omar and Uthman (may Allah be pleased with them) were usurpers and they say that 'Ali should have gotten the position of Caliph after the death of the Prophet (ﷺ).
>Is being Sufi kufr?
Sufism is considered to be a form of bid'ah (innovation) because some Sufi practices and beliefs have no basis on Qur'an and Sunnah. Some of them constitute kufr and some of them do not. And Allah the Almighty knows best.
May Allah grant you and me steadfastness and strengthen our faith.