It's my first time to design a flyer in adobe illustrator, but I have a few questions that may sound naive or easy for all of you as experienced designers. I really need your answers as I have to deliver that flyer to the client tomorrow. note that: I already watched all videos on youtube !

1) My document is 4.25 x 5.5 inch, so what should be the bleed?

2) I placed the images in my flyer design, but I can see that those images loss their quality, how can I place them without losing quality, are there additional steps after placing them? and how to make them print- ready with the highest quality as part of the flyer design?

3) How to save the flyer as a PDF for print-ready with all the images and texts added? what are the options that must be changed?