yep as @BenGitter said, you can do a sketch of your desired layout then build the structure using html. This is where you’d add all your content. You then make it pretty with css.
My inexperienced view is that photoshop more of a tool that a pro/pure web designer would use - before passing the finished file, which is nothing more than a detailed layered picture, to a front end developer to translate it into an actual; working website. I’ve never touched photoshop personally so I have no idea of the learning curve. Learning photoshop won’t do you any harm but it isn’t necessary at this stage unless you intend to or end up doing that kind of work. A PSD slicer is semi derogatory term I have seen banded about the internet to describe such developers.
I guarantee if you read this book - you will be able to build a website from scratch - then worry about making them responsive.
No such thing as a silly question on this forum. Ask away… it makes those a few steps further down the road to feel smart if they can answer
ps, someone correct me if i’m wrong, but I have read once or twice that designing websites in photoshop is a dying method.