I’d say for readability, the New American Bible, or the (New) Jerusalem Bible are the best places to start. You’ll be able to understand the English much more easily. There is a “spectrum” of translations from the more literal, word for word translations to the dynamic equivalency translations, which are more concerned with presenting the ideas of the authors in a readable fashion rather than being word-for-word. The NAB and NJB fall on the latter side of the spectrum.
Once you become more familiar and comfortable with scripture, you can get one of the more literal translations, such as the Revised Standard Version - Catholic Edition (RSV-CE) or the Douay-Rheims Bible. The Douay originally came out before the King James Bible and was last revised in the 1700’s, so if you like that type of language, that would be a good version to get (it’s also a direct translation of the official Vulgate).
Just to see the differences, I’ll post a verse (John 1:1-5) from each:
NAB
1 2 In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God.
3 All things came to be through him, and without him nothing came to be. What came to be through him was life, and this life was the light of the human race;
4 the light shines in the darkness, and the darkness has not overcome it.
NJB
1In the beginning was the Word: the Word was with God and the Word was God. 2He was with God in the beginning. 3Through him all things came into being, not one thing came into being except through him. 4What has come into being in him was life, life that was the light of men; 5and light shines in darkness, and darkness could not overpower it.
RSV-CE
1] In the beginning was the Word, and the Word was with God, and the Word was God.
2] He was in the beginning with God;
3] all things were made through him, and without him was not anything made that was made.
4] In him was life, and the life was the light of men.
5] The light shines in the darkness, and the darkness has not overcome it.
DRV
1 In the beginning was the Word, and the Word was with God, and the Word was God.
2 The same was in the beginning with God.
3 All things were made by him: and without him was made nothing that was made.
4 In him was life, and the life was the light of men.
5 And the light shineth in darkness, and the darkness did not comprehend it.