Roof pitch

I bought a very old home and I have to replace the current roof covering on an outdoor porch. It is covered with tar paper and roofing nails and all seams and nail heads were tarred. The pitch of the roof is not a very great angle at all (maybe 10-15 degrees). It is only one sided (no mid-peak).
My roof is starting to leak greatly as rainwater is collecting between the worn out seams.
My question, is this pitch to small to replace the current roofing with felt paper and shingles?
Or would it be better to cover my roof with the aluminum long roofing sheets that overlap screwed in with rubber washers that I’ve seen sold at Lowe’s?
Thanks for any advice…

Lowe’s is selling standing seam now? Hmmm. Metal roofs last way longer and are safer at low pitches. I’m not good at converting pitches to degrees, but I think its roughly a 2 pitch. Not having a peak on a subroof sounds to me like you’re running into a wall and I would hire a professional. You’re getting into more detail than I think the average homeowner would want to take on on a weekend. If it’s a 2 pitch metal roofing is a viable option, as well as rubber. What kind of siding does it run into?

After reading what I wrote, let me elaborate further about the wall. Because it is a 2/12 or 3/12 pitch, both of those systems need to be properly ran behind the wall. If its a metal roof, I definitely cant explain in words how to do it, and if its a rubber roof, well, probably the same. If it were a steeper roof application and shingles were a viable option and there were some flashing you could use already behind the wall that was not rotted, sure, you could do it yourself. You start ripping walls apart I’d hate to explain to you the nightmares I’ve discovered.