Some tips for beginner hikers:
1. Prepare your muscles ahead of time. Make sure you can walk 30-45 minutes 3-5 days a week before attempting a strenuous hike. You will use the same muscles when hiking, but under a little bit harder circumstances. Your proprioception will be tested more due to the uneven terrain which means all of those smaller, intrinsic muscles will have to come in to play and help out. If you haven't prepared your stabilizing, larger muscles for the hiking, these smaller muscles will start to get overused and you set yourself up for injury.
2. Wear good, supportive hiking shoes. I don't recommend wearing your running or walking shoes if you don't want to be cleaning mud off of them. Even if it hasn't rained in a week...there always seems to be mud somewhere on the trails! The biggest advice I can give is to make sure they are comfortable. I tend to lean towards hiking shoes than boots as they are more comfortable and less bulky. My personal favorites are the Brooks Cascadia. They were made for trail running, but work just as well for walking. They have a good amount of support, which is crucial when walking on the uneven ground.
3. Stretch your major muscles. I prefer stretching after the hike when my muscles are warm. I always hit the calves, hamstrings, hip flexors, and most importantly piriformis! Beware that your glutes and quadriceps will most likely be pretty sore after the first few times you hike, especially if there are multiple hills involved. Stretching a few times a day for the next 2-3 days following a hike can help reduce the soreness. Massage is also a great pain reducer for this type of soreness.
4. Last but not least, always hike with a buddy! It's a great motivator to get you both out and moving, but also a lot safer!