Computer Science PH.D in America advice

[nicelhc13]

Hello everyone,
I am a Masters student, preparing for my doctoral degree now.
I have been only concentrating on my work, so I lack much information.
Currently, I am doing my researches going from site to site to learn more about the process.

To start off, I want to get your advice on how much I have come so far and want to know what I can do to improve.
If there is anyone who is working the same field as an advice would be much appreciated.

1) For my Bachelor's 1st and 2nd year, I didn't do very well but during 3~4th year, my GPA is about 4.1/4.5
My major is about 4.0 and I was involved in a lot of activities. My overall GPA is about 3.9
During my Samsung Software Membership activity, I received the Technology Fair award best award in the community with embedded product.
I also recieved an award National award for making application for disabled.

2) I am currently enrolled in Seoul National University. I did my resarches on system and I was able to listed as second author in top conference.
(the first author was my professor, even though it was my idea and I took on the research. The professor promised to show this in the reccommendation.
Also I am going to present this paper during the conference.)
I also put the paper in workshop and had this paper accepted to Samsung Human Tech and SCIE journal as 1st author.
My Master's GPA is not very good. It is 3.4/4.3

3)I currently have no English score. I am going to get it by this year.
I have gotten 86 on TOFEL and no GRE score yet.

I am planning to continuously work on my research but focus on English. I will probably apply next year.

Should I focus on my resarch and try to fill my GPA?
Also please give me your opinion on what schools I can possibly apply for.

Thank you so much for taking your time to read my post!