How should I dress 7 almost 8 month old for outside all day?

I’m going to watch his cousins soccer game. We’ll be out most of the day. Baby is turning 8 months next week. The weather is going to be 57 degrees fahrenheit (14 degrees Celsius) to about 64 degrees fahrenheit (18 degrees Celsius).

Not sure how I should dress him. What would you recommend? T-shirt/onesie? Sweater? Sleeper? Should I bring a heavy or light blanket? A hat? Sunscreen? Unfortunately he doesn’t have shoes that fit him at the moment😒 he literally just outgrew them. How much sun would be too much? Should I keep baby in shade the whole time? Should I keep baby in stroller? Sorry paranoid first time mama here!