Bad quality text?

The first problem I see is that your composition frame is an odd number of pixels high. H.264 (common standard web-based streaming format) must be an even number of pixels high and wide because it is compressed in blocks of 4 pixels. Your output will be resized, and the quality will suffer.

Another potential problem is that the text is scaled to 44%, and the composition panel is scaled to 200%, so you are not previewing the actual pixels in the comp panel, and the text may be way too small. 

Cropped screenshots showing only the word "HELLO" are completely useless in diagnosing problems. We need to see the entire UI and all the modified properties of the problem layers. Press the 'u' key twice to show all the modified properties, make sure the Magnification Ratio is set to 100% (or at most 200%), and make sure the composition is selected in the Project Panel so we can see the properties. 

If the project looks fine when previewed, then you have probably customized the render settings in the Media Encoder (preferred for h.264) or the Render Queue/Output Module. 

It would also help us help you if we knew how you were planning to share your final video. If it is on YouTube or Vimeo, stick with standard frame sizes and frame rates.