welcome to the forum!!
what area are you in? hopefully somewhere that gets cold - that will solve the 3-foot
weed problem, lol!!
seriously, if you are in an area that gets cold, just wait until the
weeds die and then take a
weed-wacker and chop everything down to ground level - that will work for the sapling issue as well.
you'll still need to deal with things so that you don't have the same problem next year.
the raised beds are a good thought...you'd still have areas that will get weedy...could put down some stone paths so that you could just meander through the raised beds. either just flagstones or make pathways and put plastic down to keep
weeds from
growing and then put down a good thick layer of pebbles.
if you don't want to do raised beds, after you get the
weeds and saplings cut down to ground-level, pick an area to start off with - and mark it off...simple paint-stirrers or small lengths of wood hammered into the soil(?) will do and then tie string to them to enclose the area.
you are on the mark with the thick layer of newspaper and then adding topsoil. if the
weed issue is that bad, at least 10 sheets of paper and then 6-8 inches of good topsoil (properly amended). after you
plant stuff, put down a good layer of mulch, too (i like licorice root mulch).
once you get one area covered with the paper and topsoil, move on to another section and continue on until you get the whole thing done.
if you have areas that don't get covered before
spring, you can treat with pre-emergent stuff to keep the
weeds at bay...later in the season, spray with post-emergent to get anything that still managed to grow (
weeds are funny like that
).
you must, must, must! post 'before' pics - we'll need something to compare the 'after' pics too!!! plus, if we can see what you're working with, we may be able to come up with some ideas to make the project go a bit easier...
there are a ton of talented people here - and all of them have GREAT ideas!!