Considering PhD in linguistics without linguistics background

[turathophile]

I hope this forum is the appropriate location for my question. I am seriously considering a PhD in linguistics in the next couple years. I say the next couple years because I don't have a background in linguistics and assume that I will need some time to prepare so that I can create a competitive grad school application.

A little bit of background on myself. I am 29 years old (American), and in college I majored in International Studies and French, with double minors in Arabic and Spanish. I went on to study Arabic in Egypt on a Fulbright and then did a Master's in public policy in France at Sciences Po. Since my MA, I worked in several international institutions in Europe in policy-related positions focused on the Middle East, and for the last 2 years have worked as a senior researcher at a think tank in Saudi Arabia also focusing on policy. For 3 consecutive summers I also managed an Arabic language immersion program in Oman for American students.

So what do I want to do with linguistics? Well to be honest I have always had a sincere interest in linguistics after taking several linguistics courses in college, and after living in the Arab Gulf I have become even more interested in child language acquisition in the context of cosmopolitan/multilingual societies. Specifically looking at Arabic diglossia and the effects of globalization and especially English on children's native language acquisition in countries like the UAE where the expat population is greater than the native population and almost all education is done in English. While these are topics that interest me, I understand that maybe they aren't strictly linguistics related. These aren't necessarily topics I want to explore during my PhD, but I would like my PhD to give me the skills to address these topics afterwards. After getting my PhD I plan to move back to the Gulf or the Middle East and teach linguistics at a university there while exploring topics such this and more broadly diglossia and language acquisition. I would also like to become an expert on child language acquisition in multi lingual households, especially focusing on families where Arabic is one of the languages of the bilingual household (considering the diglossia factor). Having a PhD from the US would almost guarantee me a teaching job in the Middle East, and PhDs in this region are pretty much expected at some point if someone wants to be taken seriously in their field regardless of the field and regardless of someone plans to teach (here even lawyers, doctors and engineers regularly obtain PhDs.

So here are my questions:

What would an ideal study plan look like for someone who has the same learning and career goals as me? What types of linguistics programs should I be looking at? I am thinking a combination of applied linguistics and sociolinguistics with cognitive science. I don't want to do TESL/TEFL and I have noticed that most applied linguistics programs focus on this unfortunately.

What preparation should I undertake in these next two years to make my application more competitive? Would online courses in linguistics help at all? I am currently based in Saudi Arabia with limited access to linguistics courses unfortunately so online is really my only option at the moment.

Any recommendations for reading material to gain more familiarity with linguistics its different branches?

Any other advice is welcome!