OK,

In 4/4 you're going to be strumming 2 notes per beat. The symbol that looks like a 7 is a rest - play nothing. The 'X' means to hit the string muted to give a percussive click, and then the rectangles are normal 'notes'.

you have a few variations there, but think of it as 8 even strums per bar - just substitute the rests and clicks (x) where necessary instead of letting it ring. In the second example there is a bar of 'D' which is a little different. Three strums, the third of which lasts the same time as the first two together.

With tab, listening to the recording is your best guide. Rhythm notation can be helpful, but listening to the record is way easier if you can...