Though it is possible to travel to several places across Nepal without a guide or a porter, it is advisable to hire them before starting the trek from Pokhara. It is all the more critical when you are traveling solo because these people know the trails by heart and protect you against any unprecedented danger. A guide will also educate you about the history of the land and tell you stories about the sites that fall within your trails. A porter is particularly important when you travel with a group since they will help you carry luggage.
You should interview them well before hiring them. However, if a reputed travel and tour operator is arranging for your trek, they will recruit the guide and porter themselves. A porter's daily charge is roughly between 10 to 15 USD, whereas a guide costs approximately 30 USD each day.