Taiwan has no relationship to HK.
My understanding as an outsider:
Taiwan is governed by the Republic of China (ROC), which regained control of Taiwan in 1945 after the Japanese pulled out. ROC was overthrown my Mao's Chinese Communist Party (CCP) during the Chinese Civil War and lost control of the Chinese mainland allowing the CCP to form the People's Republic of China (PRC). The ROC retained control of Taiwan. Taiwan has always been independent from the PRC and CCP.
This completely ignores the actual native Taiwanese people who may or may not consider themselves Chinese. That is a topic I can't even begin to comment on.
The takeaway from HK in the context of Taiwan is that the People's Republic of China did not hold up their end of the bargain with the UK in HK so there is no reason to trust them in any agreement of "reunification" in Taiwan if the terms are anything other than complete submission to PRC rule.