>>266
Well, what I would do is pick two, maybe three kata, and use that as a base. The idea is to develop "karate movement" based on the form, while diving in to the bunkai, using other's analysis as well as your own. The kata contain everything, the biomechanical principles of their style, and they are conditioning tools as well as the "books" containing the technical content of a style. You'll want to start practising these kata once per day, and eventually working up to many daily repetitions. Some Chinese practitioners would practice their main form 30 times a day, and gongfu forms tend to be much longer than karate forms. Naha-te schools on Okinawa would train their students in Sanchin kata for 3 years (of daily practise) before they allowed them to learn or practise anything else, and it was considered to take 9 years to fully master Sanchin kata, as exemplified by the saying three years the stance, three years the step, three years the strike.
Some resources:
http://www.iainabernethy.co.uk/
He mostly works on Shuri-te kata application, so being from a Shotokan background you'll be working from the same pool of kata. He has a really solid, common sense, no-nonsense approach. Maybe check out his youtube videos to start.
https://www.wayofleastresistance.net/
This guy stopped updating his blog in 2018, and also turned into a bit of a faggot if you ask me, but there is still a lot of really good material on body mechanics and general principles. He's a Goju practitioner so his kata are from the Naha-te group, there probably won't be any that you practice specifically. He also talks about the "internal" styles (Taijiquan, Xingyiquan, Baguazhuang), the principles of which I think every martial artist should try to understand, even if they don't practise them.
https://ryukyuma.blogspot.com/2014/05/systemantic-exploration-of-kata-bunkai.html
Another Naha-te guy, but once again, a lot of really good general information and kata theory. He also touches on kyusho-jutsu.
All these guys have jewtube channels, and I'd look into those, as well as Rick Hotton, he's a Shotokan guy who has really good movement, and is an excellent teacher who actually can and does explain the "whys" and "Hows" of what your doing, which is really rare. I posted one of his videos as a webm here >>135
Also, read the screencaps posted in this thread, I picked most of them very carefully. What's posted here could transform most people's martial arts if it was put into practice.
In case you're not familiar with the terms "Naha-te" and "Shuri-te", it is a distinction between the two major branches or styles of karate, similar to the distinction between "Northern fist/Beiquan" and Southern Fist/Nanquan" in gongfu. Each uses a separate family of kata. Shuri-te is uses the classic 3 stances (front/bow stance, horse stance, cat stance) reminiscent of the mainstream Shaolin styles as a base, is known for speed and agility and long range fighting. It's considered ideal for smaller framed people. Examples of Shuri-te are Shotokan and Shorin-ryu styles, and the kata Naihanchi, Tekki and Niseishi/Nijushiho. Naha-te is derived from Southern Chinese styles that also use Sanchin/Saamchien as base, like White Crane, and may be a distant relative of Xingyiquan. it's much more upright, and tends to focus on short range striking and in-fighting with clinch work and joint control. It's considered ideal for stockier types. Examples of Naha-te are Goju-ryu and Uechi-ryu, and the kata Sanchin (obviously), Tensho and Suparimpei. Some styles, like Kyokushin and Shito-ryu incorporate kata from both groups. It's rarely a clear cut black and white situation, and you'll find elements of both everywhere.
As far as a specific training routine, do some research on Hojo Undo, which is karate specific strength training (see pic related for results) and just think about what you used to do in class. Try to use that as a base and build on it. I know you probably won't have partners to spar with, so make sure to try and replace that with time on the punching bag. Make sure you get time in actually hitting something at full power. Read about what the masters used to do and start working up to it. I believe Funakoshi himself recommended 30 minutes a day for solo training, split between kata and hitting the makiwara. Other guys trained until they pissed blood. What works for you will be different than what works for someone else.
>books
There are a few books I can recommend, but really, as first priority I would just buy a hard copy of Patrick McCarthy's Bubishi. It's required reading for karateka of all styles. Treat it like a bible, read it, reread it, leave it alone for a while then come back to it. It will set you on the right path if you take it seriously and think about what's implied, rather than outright stated.