There are many ways to get to Pakse from different parts of Laos.
Lao Airlines offers domestic and direct international routes. Domestic flights are from Luang Prabang, Vientiane, and Savvanakhet; while the direct international flights are coming from Bangkok (Thailand), Ho Chi Mihn (Vietnam), and Siem Reap (Cambodia).
There are daily sleeper buses coming from Vientiane, while public buses coming from nearby provinces of Savannakhet and Thakek are aplenty. International buses from Ubon Ratchathani (Thailand) travels twice a day to Pakse and vice versa. There are also vans coming from Cambodia and Vietnam.
Check with the appropriate consulate or embassy in your country to find out if you will need a visa to visit Laos and the requirements you might need to bring.
There are several ATMs in town to get money from. BCEL and BFL banks accept international credit cards when withdrawing money. USD, EUR, THB can be easily exchanged to Kip in the city center.