Wearing the proper clothing is important to the enjoyment of your hike. Cotton is always a no no because it tends to keep heat in and does not dry quickly when you are either sweating or getting rained on. No blue jeans either. They are just too hot.
You don’t have to spend lots of money on hiking clothes and you don’t have to buy a lot of clothes. I would think one pair of long pants especially for hiking (with zip offs would be nice) and a good sturdy pair of hiking shorts. I have a nice pair of Columbia shorts that have been very sturdy which I have been wearing for at least five years but are close to retirement due to the numerous holes I’ve worn into the backside from sliding over rocks etc. Nobody really cares what you are wearing on the trail as we aren’t out here for a fashion statement but a couple short and long sleeve hiking shirts are a good investment. I bought a couple inexpensive long sleeve hiking shirts at Kohls last winter and so far so good.
To me, hiking boots are my most important investment. If my toes are hitting the end of my boot and starting to hurt, it won’t be long before I can’t hike any more so I tend to spend a little more money on my boots. In fact, many stores do not carry a big variety of women’s hiking boots but you can always shop online (man or woman). I tend to beat my hiking boots to death as I probably don’t give them nearly the care they deserve but I would think you should get at least 3 or 4 years out of a pair of boots with average wear. I like the boots with the higher support for the ankles but many people hike with what they are calling low hiking boots which fall below the ankle. I think the more rugged the terrain you plan to hike, the more care you need to take in making your boot choice.
I always wear and carry at least one bandanna in case I need to cool off by dipping it in a stream or to tie up a broken leg! Just kidding (I think). There are numerous uses for bandannas and a good Boy Scout always carries one!
Knee high hiking socks are a plus. Sometimes you can pick up some good socks at Sam’s (not a plug) which are perfectly acceptable for hiking. I typically own two good pairs of hiking socks at a time and that will get me through a weekend. I know they tend to be a little expensive but well worth the money. Sometimes I wear shorter socks in the summer but the higher socks do keep your legs from getting all scratched up.
Layering. You might like to wear a vest in the winter and also carry or wear a shell that helps block the wind. I would suggest you bring another pullover to wear under that. If you get hot, you can take it off. Long underwear in the winter is also good if you buy the thin kind. I would suggest in the summer that you bring a wind breaker in case you get a little cold. I would also pack a rain jacket or rain gear.
Hats. I like my orange baseball cap in the summer although I have a fancy Tilley Hat that mostly sits in the closet. In the winter, I wear a winter cap and gloves, and a scarf. Pick the hat you like as long as it is somewhat breathable. You do want a hat because it will help keep the hot sun off your head and help keeps heat in during the winter.
I think the bottom line is that you really don’t have to spend tons of money to have a decent hiking wardrobe. If hiking is your passion, you may want to invest a little more in products that have some longevity as well as quality which I suspect will save you in the long run.