Tobias Branston, 19, from Shifnal, will set off alone from Land’s End on Tuesday on a two-and-a-half month journey to John O' Groats.
He will be raising funds for Severn Hospice and Heartburn Cancer UK after two close friends lost fathers to cancer.
"I'm currently in the midst of a year out between school and university," said Tobias, who will be studying classics at Exeter University later this year.
"I went travelling in Thailand recently which was amazing but given I have some months now before I go to university, I wanted to do something worthwhile.
"It's quite rare to have time like this, totally free, so I started exploring different charitable options.
"Two of my oldest friends have lost fathers to cancer. They were both in the military and so it seemed appropriate to attempt a particularly demanding feat and support these two worthwhile charities."
The adventure will see Tobias, unaccompanied, take on a route of more than 1100 miles on foot, walking up to 25 miles per day.
Tobias, who plans to join the Army after university, will be sleeping out in a bivvy bag rather than staying in Bed and Breakfasts, hostels or hotels in order to maximise the amount he raises.
"My dad – Barney – was in the Welsh Guards and they have been amazing," said Tobias. "They have helped me out, with lots of kit and plenty of advice.
"They have told me everything from basic things – maintenance and hygiene – to physical and mental health advice.
"I'd taken the mindset I was going to crack on and push myself as much as possible early on.
"But they told me it is vitally important to take rest days, rest the body and make sure I am on top of any niggles.
"I am just looking forward to the challenge.
"I'll be pushing myself out of my comfort zone, discovering more about myself and what I can and can't do."
The Severn Hospice cares for people at the end of their life, providing an inspirational degree of wrap-around humanity, kindness and care not only for their patients but also for their families.
Heartburn Cancer UK raises awareness about the dangers of persistent heartburn, gastro-oesophageal reflux disease (GORD) and Barrett’s oesophagus which can lead to oesophageal cancer.
A quick and simple cytosponge test, developed by the University of Cambridge, is currently an NHS pilot using mobile diagnostic units run by Heartburn Cancer UK.
Oesophageal cancer is the fourth most common cause of cancer deaths in men in the UK.
You can follow Tobias' journey on Instagram on @tobiaswalks and he can be sponsored at justgiving.com/crowdfunding/tobiaswalks