In Proverbs 8 we are given some of the thoughts of the Son of God before creation:
The Lord possessed Me in the beginning of His way, before His works of old. I was set up from everlasting, from the beginning, or ever the earth was. When there were no depths, I was brought forth; when there were no fountains abounding with water. Before the mountains were settled, before the hills was I brought forth: while as yet He had not made the earth, nor the fields, nor the highest part of the dust of the world. When He prepared the heavens, I was there: when He set a compass upon the face of the depth: when He established the clouds above; when He strengthened the fountains of the deep; when He gave to the sea his decree, that the waters should not pass His commandment: when He appointed the foundations of the earth: then I was by Him, as one brought up with Him; and I was daily His delight, rejoicing always before Him; rejoicing in the habitable part of His earth; and My delights were with the sons of men. Prov. 8:22-31.