(In the Name of God, the Most Beneficent, the Most Merciful)
Welcome to our humble abode here, IB sis in humanity!
I went from atheism to Islam. So, I relate to your attraction towards Islam. Moreover, there are a lot of converts on this board, though I also want to give you a heads-up that there are sometimes here some ignorant posts, which you'll want to disregard.
Sis, converting to Islam is easy: The moment you believe in your heart that there is no god but God and Prophet Muhammad (peace and blessings be upon him) is the messenger of Allah, you already become a Muslim. Allah (God) knows our intentions and our heart as nothing is hidden from the All-Seeing. That said, new converts are encouraged to introduce themselves to the Muslim community by taking their shahada (testimony of faith) at the mosque.
Sister, I try to tell this especially to new converts: Take things one step at a time. Walking this path is a journey, and you'll feel very excited about doing things all at once, but you have to also remember the saying "Rome wasn't built in a day" and try to not overwhelm yourself. Please do read the article "12 Tips for the Convert Muslim."
On some of your concerns:
Since you have tattoos, just try to cover them and in the meantime you can have long-term intentions towards perhaps removal if that's a feat that's not something that is too difficult or affordable at some time in the future; remember though that Islam wants ease for you; and therefore, please do not be concerned if these things are not immediately something you can accomplish. Remember Islam is based on intentions for each action or inaction. So, always have the best and most beautiful intentions whether you're achieving them or not.
Sister, I will tell you that your romantic relationship will be a harder battle as yet for you; while I do advise you to remove yourself from your boyfriend if you don't see him as sharing your faith, I do understand that matters of the heart are not as easy. This is something with which you'll struggle, but I do want to tell you that everything that you give up for Allah (as all, including people and things in our life are gifts of Allah), trust that Allah will give you of something that's an equal weight or replace it with something better. Please read this post called "The Non-Muslim Husband: A Lesson" from our wise and older sister on this board, which might give you some perspective on your own situation, though I emphasize we're not here to pressure you in any way but to sincerely support you on your journey to and within Islam.
Again, sister, with the diet, try to ease yourself into it; do not overwhelm yourself. If you cannot find halal foods, you are always free to eat kosher foods. And all the veggies and fruits in the world are your best friends and fishes too! Hehe.
Sister, this is your journey; if you do not feel comfortable yet wearing a hijab, then don't wear it, because remember the end-goal is to take one step at one time and not turn this experience into something suffocating or terrible for yourself. I can tell you that when I started wearing hijabs, I started with hoodies. I will also be honest with you and tell you that the atmosphere in U.S. is tense and uncomfortable, especially since the elections, so that I do recommend that if you honestly feel you're going to become a target of harassment or anything worse, then you please do protect yourself and not feel compelled to don a hijab. Remember that Allah does not desire us to put ourselves in jeopardy and we're allowed to hide our faith if we should feel threatened in any way; I do remember being forwarded a scholarly opinion on email on this subject some time ago. This is not to say, dear sis, that we should not desire to don the hijab but that some situations are worse for some people than others, and you'll have to listen to the voice of both reason and your heart to reach a conclusion on this matter.
Things might sometimes seem bad, sis; but there's always a silver lining to everything, and I'm an eternal optimist thanks to Allah. So, I also want to just repeat my welcome to you, beautiful sis, on this board and to Islam.
Sis, feel free to PM me for anything whatsoever; I would be very happy and honored to support you in your journey as your servant and sister in Islam.
Best Wishes & Sincere Regards,