I’m really interested in learning more about Sikh beliefs in Moksha. Do Sikhs believe jivas are eternal? When we reunite with God will we retain our individuality?

Amanpreet Kaur Ji Mokska in Gurmat is from ardent worldly temptations while alive, not after death. That is called Jeevan Mukat in Gurbani.
ਜੀਵਤ ਮਰੈ ਮਰੈ ਫੁਨਿ ਜੀਵੈ ਐਸੇ ਸੁੰਨਿ ਸਮਾਇਆ ॥ ਅੰਜਨ ਮਾਹਿ ਨਿਰੰਜਨਿ ਰਹੀਐ ਬਹੁੜਿ ਨ ਭਵਜਲਿ ਪਾਇਆ ॥੧॥ AGGS 332
Jivat Marai Marai Fun Jeevai Aise Sunn Samaeia || Anjan Mah Niranjan Reheai Bahurr N Bhavjal Paeia ||1||
Bhagat Kabir says someone who dies again and again from ardent worldly temptations and controls the mind (Mann) of worldly passions (Maya) then one lives a perfect spiritual life. Such a person dies spiritually many times a day and has lived spiritually many times a day merges into the Primal Void of the Absolute God while living and will never get into the cycle of spiritual death and birth. Remaining pure in the midst of impurity of worldly passions, one will never again fall into the terrifying world-ocean of Maya.
Soul after death merges with the Primal Void (Originator).
ਸੁੰਨਹੁ ਖਾਣੀ ਸੁੰਨਹੁ ਬਾਣੀ ॥ ਸੁੰਨਹੁ ਉਪਜੀ ਸੁੰਨਿ ਸਮਾਣੀ ॥ AGGS 1037
Sunnhu Khaini Sunnhu Bani || Sunnhu Upaji Sunn Samani ||
Everything was created from Primal Void and will merge with Primal Void after death.

ਪਾਂਚ ਤਤ ਕੋ ਤਨੁ ਰਚਿਓ ਜਾਨਹੁ ਚਤੁਰ ਸੁਜਾਨ ॥ ਜਿਹ ਤੇ ਉਪਜਿਓ ਨਾਨਕਾ ਲੀਨ ਤਾਹਿ ਮੈ ਮਾਨੁ ॥੧੧॥ AGGS 1427
Panch Tat Ko Tann Rachiou Janhu Chatur Sujan || Jih Te Upjiou Nanaka Leen Tahi Mai Maan ||11||
This body is made of five elements and will merge into that after death. Soul (Atma) came from God (Supreme Soul) and will merge with God (Supreme Soul) after death.
For more information on such topics you can read my books GURMAT DOCTRINES (PART 1) and (PART 2) available on amazon.com