Problems with uploads etc!

I am new to website operations and drowning in my own lack of understanding. If someone might point me I would be so grateful. I have tried reading the 'help' pages but cannot find anything to address my particular problem.
Can I completely 'clear' my website and then upload another by simply 'deleting' all the files that show up when I connect SmartFTP?
I have been doing this but when I do I still have some 'old' pages coming up when I visit the site (although the website has no files showing when I 'connect' SmartFTP).
My site is 10 pages and pages 1&2 are fine (the updated versions) but pages 3 onwards are all 'old' pages and I cannot see where they are coming from.
I am a novice, but if some non-too- technical advice was available I would be most grateful - at present website design is about to be thrown out of the window (with the computer!!).
Thanks

Can I completely 'clear' my website and then upload another by simply 'deleting' all the files that show up when I connect SmartFTP?

Yes. Just be sure to be in the right folder when deleting files. Depending on your host, the files that make up your web site are maybe not in the folder you're in when you login, but in a "public_html" folder.

I have been doing this but when I do I still have some 'old' pages coming up when I visit the site (although the website has no files showing when I 'connect' SmartFTP).

If that's not related to the issue above (you have deleted all files in the root, but not the files in "public_html"), this might be a caching issue. Reload the page in your browser while pressing SHIFT (this forces a real reload of the page in most browsers).

Thanks for that info - the problems I had seem to have sorted themselves out, meanwhile.
I hadn't realised there could be a 'public_html' folder! Will need to do some searching now the immediate preoblem seems settled.
Thanks again.