Other than SSD 1 and AT level 1, what other online training can you do to get ahead?

SPC (Join to see) while it is way above anything that you would do at your rank their are courses you can get promotion points for such as the Additional Duty Safety Officer and the Commander's Safety Course. Last I checked they were 8 hr and 16 hr courses. If you ever want to be E7 or commission you will have to do the CSC.

You can also try online college courses to get some points there as well and look well rounded with both Army and college courses.

Looks like you are leaning forward. Keep it up.

Cyber awareness, (sign AUP), GAT 2.0, SERE 101.2, just to name a few

Not sure of your status, but if you are Reserve Component, look into EBDL- electronic based distributed learning. They have quite a few courses available (many mandatory, to include SSD) and you can get paid to complete it. Your unit should be able to provide you with a list of classes and process your for pay as well.

Do civilian education before military education. It will pay off in the long run.

Focusing on on-line courses do help, however you need to attempt to get into some residential institutional training as well. The AT Level 1 is a 350-1 training requirement and is mandatory for all Soldiers, so this will not get you ahead it will just keep you current in your mandatory training. Try to get schools like Air Assault, Air Borne, CLS, Generators Course, Field Sanitation Course, Combative, anything in this realm. Always push for schools that will set you up for success. These schools are not intended to help you with your MOS proficiency, however they will help you to become a well rounded leader.

SPC (Join to see) To get ahead on your MOS, look for correspondence courses that deal with your area of expertise, now if you want to stay ahead of your units mandatory (fun) online training, get your company training guidance and knock out all of them ASAP (usually AT, OPSEC, SHARP, Accident Avoidance, etc)

Lots.
I would start in ALMS and look up courses that can supplement proficiency in your MOS.
After that, there are many opportunities to broaden your skill set with courses on such things as commo gear, marksmanship, and many others.
Learning a language is also of great utility. Many units have access to commercial language training software and testing out at certain levels of language comprehension can get you FLPB payments in certain MOSs.

Accident Avoidance, Composite Risk Management, GAT 2.0, SERE 101.2, Army Cyber Awareness Challenge.. Those are the big ones that I can pull off the top of my head.

SPC (Join to see) Correspondence courses, and have you started College? That gives you 1 point for every complete credit hour.