Kythera is accessible by ferry from the ports of Piraeus, Gythio and Neapoli. It is also connected by ferry to Kastelli port in Kissamos (Crete) and Antikythera. For itineraries you can click at the following link: http://www.openseas.gr/openseas/en/
Kythera have an airport connected to the Athens and Thessaloniki International Airports. For itineraries you can click the following link: https://www.google.com/flights
To move while on the island of Kythera you have many options. Either to use your own vehicle, rent a vehicle, travel by bus, or by taxi. For bus schedules you can visit the following link: https://visitkythera.com/en/leoforeia/ Taxi contact details can be found at the following link: https://visitkythera.com/en/taxi/
In Kythera you can walk all year round. Hiking is also possible in winter, but the chance of rain is higher. In winter the wind can be strong and icy. Summer (July, August) is very hot for walking. However, if you try it, please avoid hiking between 12 and 4pm. Spring and autumn are considered to be the best seasons.
Hiking boots, hat, sunscreen, long trousers, walking poles are considered essential. It is also advisable not to walk alone and to always keep with you a first aid kit. A torch, and a well charged mobile phone are also advisable.