Here's a little test of your ability to read music without a time signature. This is the theme from a piece by a very well known composer - note, I transposed it into a different key because the original key might frighten some people. Which is the correct version - 3/4 time or 4/4?
(I'll add a link to the original after a day or so, to give the OP time to answer the question)
Apparently the OP didn't bite, but it's not a (rather insipid) little waltz or minor-key ballad in 3/4 time, which is what the first version would suggest.
The 4/4 version is actually the subject of a Bach fugue (BWV 853): see page 3 of https://www.pianoshelf.com/sheetmusic/735/bach-bwv-853---wtc,-book-1--prelude-and-fugue-no.-8-735