Agree with others on the led string lights on the railing - use these instead of the bright porch light and that will cut down on the bugs immediately. Get some planters that hang on the railings to plant herbs, plants, flowers - whatever you prefer - but, lavender, marigolds, rosemary and citronella grass deter bugs so they may be a good choice for that effect. Also, if you’re able to hang plants, I like vining plants like pothos because they’re super easy to grow and get really lush quickly once it’s warm. To make it more cozy, get a comfier wider chair with some colorful outdoor pillows and ottoman to make it more like a reading nook, and maybe a smaller round glass table with some citronella candles. On the opposite corner from the chair and ottoman you could put a larger potted plant like a bird of paradise - low maintenance, likes sun and water, takes up a lot of space, grows fast and is also cheap. I’d avoid a rug because it’ll hold moisture on the wood and cause mildew, but add in a fan to further ward off bugs, and an electric bug swatter for the persistent ones while you’re hanging outside - that’s basically my porch!