Fascia & soffit info

Al393

I need to install a single pitch roof over my trailer. I will be using 2x6 rafters and plywood. I want to put metal roofing over it and over my existing porch roof. Ten foot lengths for rafters and metal roof sheets seems to work out fine. I'm very fuzzy on soffit, fascia, and F or J trim materials. I want to keep it simple, just need to keep water from running down the trailer sides in rainy weather. Would like to have the soffit follow rafter angle up. Need to assure no wicking of water under edges. I've read some of the Q & As already but still am unsure of best choice of materials. I haven't done a roof before. Can't afford to hire it done nor make major materials purchase errors. Hard times. Would appreciate some insights. Thank you. Al