i'm going for a 5 day hike in the belgium ardens in about 1.5 months from now, but i don't have a backpack yet and i have zero experians with long distanse multi day hiking, so what are the points you have to look for wenn buy a large hiking backpak, exsept that it has to big enough and fits comfitable ?im on a low budget so any good tips of some good cheap packs ?
any tips over hiking would be nice 2....

the trip will be made with 20 other non-experians folks and 5 guys who has 20 years experians....