Blisters will likely be your main problem. Here is what to do:
Watch it and act
As soon as you feel the first rash developing, do something. Never procrastinate. It’s a life-lesson, really: handle your problems before they grow bigger. Same with blisters.
Blister tape or sports tape. Make sure the exposed piece of skin is protected. Take off the dressing during the night to let the skin breathe.
If you are having trouble with blisters in-between your toes, then consider wearing toe socks, such as injinji.
Avoid grit and rinse
Make sure your shoes and socks are grit-free: Shake and dust off your shoes/socks regularly, especially if it’s a sandy trail.
The very fine sand, called silt, can be difficult to shake off and will mix with your sweat to create some nasty cakes on your feet and socks. Wash! Take your time to wash your feet and rinse your socks, if there is a creek or large lake. This means that you should carry at least 2 pair of socks, in order to wash, hang-dry and circulate them. Mini-gaiters (such as Dirty Girl) is good at keeping grit and pine-needles out of your shoes and very popular among thru-hikers.
Be decent: other hikers might need the water so always wash downstream and a little away from the trail. Never ever wash socks in a water trough, as others will be drinking from this trough.
Ventilate and stay dry
Take your shoes and socks off and let them dry out, everytime you take a break. Humid, overheated feet is a blister farm.
Try to avoid getting wet shoes: Take them off if you have to ford a creek. Obviously you’ll get wet shoes if it is raining or when you walk for hours on end through snow. Rinse your socks and hang them to dry outside your backpack, when the sun is back.