First of all lets talk about rose, should not be in that position, just one horizontal position, not like bending towards one side, placement is good, just change its positioning.
2nd about the logo, when Aany said the color changed because background image was brown, thaz not the case, when u paste a new image on any image color doesn't change to he background image, u changed the color on purpose that is good, because it looks nice with te background image. the lower its capacity just do what aany said, use Opacity and decrese it to 50, 75 or 25 whereever u see its good, just change it to that value.
now about text, it will improve with practice, again the text is not that good, u'll need to learn inpage, max effetcs are acquired thru EPS format files, this copy pasting takes loads of time and work, try to lessen yr work. and instead of moving the bottom line to one corner, change the colors, in this shape text doesn't give any good impression, it seems something's missing, change the color, use different effects to make the text more visible, u do not have to stick with just one color and affect, play arrounf with different tools, like in this case, u could have used INNER SHADOW, and see what kinda effect brown or red shadow gives u, what will happen if u add stroke in addition to that affect, may be lil emboss will improve the visiblity od the text more, use all tools and play with them, this will show u more options tht u can use.
1- open image (background)
2- if anyoter image is to be merged with that, open that, select , copy, and paste ..... prepare yr desired image, by using blending tools.
3- open text , paste it.
4- use blending options to make it nice.
5- put the frame.

thaz it, einstein said thinsg should be kept simple, not simpler.
when u know how to use all blending options, then u can go to harder steps to play arround with backgrounds. if