My five cents, as someone learning Japanese while currently living in Japan:
First of all: Deep breath! Obviously nothing is going to magically stop the idea of “moving to a foreign country where I don’t (fluently) speak the native language” from being some level of scary, and to be fair there are a lot of challenges to doing so, especially depending on how much outside support you have for the process.
That said, try not to let it tie you up into too many knots. (I’m not kidding about the deep breaths!)
If you’re going to a more urban area, I guarantee there will be at least a decent level of English support in your daily life – things like train station names, English labeling at the コンビニ, cashiers who know enough English to go “bag?” when you blink in confusion at レジ袋. If it’s more rural things might be a bit trickier, but there’re still resources, you just might have to go looking for them.
Point is, don’t let your current skills get you too worked up. The immersion will be really good for your learning, and I’m sure you’ll find a lot of things over here that you can enjoy regardless of your fluency.
As for your actual question, my first reading practice was in a college classroom so that’s probably not an option for you. That said, my current system is to read manga that I’m very interested in – to counter the “Oh god this is so hard why am I doing this to myself” sensation with “holy shit it’s my boy Heiji I’m so excited for this chapter-” – AND that I have read before in English.
By going with something I’ve read before, even ages ago, I know at least the broad strokes of the story and characters involved. It’s manga, so the visuals do provide some support for what I’m trying to read at any given moment. Personally, I look up words if I truly can’t understand the sentence without it but I don’t try to add them to SRS – odds are they’ll pop back up shortly, and I don’t want a massive pile of SRS for every single word I don’t know.
My current poison of choice is 名探偵コナン, which also means there’s a lot of normal daily language in it as opposed to what you might find in, I dunno, 鋼の錬金術師(fma) or 青の祓魔師(blue exorcist).
Yes, this ALSO means there’s a lot of murder mystery and criminal investigation language/kanji. Which is harder, but it’s also kinda funny to see someone’s reaction when I know the word for “victim” but not for “hallway”.
Once you get over here, if you want to look into manga or other hard-copy reading practice, check out someplace like BOOKOFF, which is a Japanese secondhand book store. Japanese second hand stores tend to have very good condition items. I can’t tell you how many volumes of manga I’ve gotten for 300 or even 100 yen, and the only sign of age is some fading on the spine or the odd dented cover.
But tldr; I read something that I am highly interested in and have read previously, and look vocabulary up as need be.
EDIT: Sorry about the accidental reply, Escalus, I had meant to second your comment about never feeling prepared but lost track of the thought. I definitely agree, though, I never feel prepared 
