Let’s learn Japanese with manga. What you are going to learn on this page is:
今はまだその時じゃない！
今はまだその時じゃない
(It is not the time yet.)
今（いま）means ‘now’. は is a topic marking particle and does not mean anything.
まだ is used with a negative word such as ない. It means ‘not yet’. その means ‘the’ or ‘that’. 時（とき）means ‘time’.
じゃない means ‘not’ and follow a noun.