Shortening the prayers is a confirmed Sunnah for all travellers, whereas joining the prayers is permissible but is not Sunnah, but it may be Sunnah and recommended if there is some difficulty involved in not doing it.

Praying Tarawih is recommended for the traveller as for the non-traveller because Prophet Muhammad (peace and blessings of Allah be upon him) persisted in praying qiyam al-layl whether he was travelling or not.

If going from your city to this place is regarded as travelling according to the people`s customs, then it is not permissible for you to go there without a Mahram. If it is not regarded as travelling according to custom then there is nothing wrong with you going there without a Mahram.