a) Keep an eye out for anything that could prove useful. Explore but be carefull, lots of ways to get sick or hurt (or dead). Your first goal is survival so take care of your basic needs, food, water, health, clothing. Get familiar with your Computer and Medical Kit. Avoid some battles untill you're better equipped, so run away or sneak by (crawl) if you think you're in over your head. Be extra sure about each step on dark places. The aim is survival and ultimately escape.
b) Roam. Choose wisely when it comes to places to sleep to avoid nasty 'surprises'.
c) Unless you're asking for spoilers about the specifics, test stuff out. You can make clothes, rudimentar weapons, fishing rods, traps, etc.