This might sound a bit silly but give it a try: Add the N5 Kanji (Beginner Kanji) mastery schedule to your dashboard (go to "Manage schedules" link to add), click on Settings on it, and there should be a setting labelled "Currently studying:" From there, try starting out with only "meaning" and "writing practice" (if thats available). If you click "Settings" on a schedule, another link will appear labelled "More settings" and from there you can adjust how many new terms per quiz, etc. Set it to something like 5 or 10 for starters, cap it at 20 per day, and then just spam the quizzes.
Fair warning, it's gonna feel super uncomfortable. If you're cool with that, jump in and start. It will keep dishing you back the ones you miss, and trust me even if it doesn't feel like it, you WILL start getting the wrong ones right after missing them enough times. Check the mnemonics on them, think of a little story in your head, whatever you gotta do to help make it easier is cool too! Just try to grasp the meaning of each one and learn to know em when you see em. After that, start adding in on/kun readings from Settings, when you feel comfy. Above all there's no rush and you're absolutely 100% positively gonna forget em constantly. It's just a struggle. I'm there right now with ya. Just let em sink in over time and spam quizzes and there's also a "Focused Review" so do as many of those as you want too. Remember wrong answers are a very good thing so a low quiz score means you are learning more and is much more valuable.
Anyway sorry its a long comment - good luck out there!
I was going to ask the same question today. So thank you for asking, and thank you for the wonderful answer, which has already helped. I’m pretty good at catching onto the meanings of the kanji, but with the constant shifting between onyomi/kunyomi, I was feeling like I was guessing more often than not, and not able to pin them down to secure them in my memory. I have followed your advice, and changed the settings to meaning only for now. I think that makes it much more manageable. Before I didn’t even know where to focus with the mnemonics, but now this narrows down the focus considerably. And like you recommended, I will add in the onyomi and kunyomi later. Thank you for taking the time to write out such a clear response.
If it's readings you're struggling with, I suggest going into your schedule settings and first disabling the "onyomi or kunyomi" advanced question type (the one that tests you on whether readings are on or kun); I think it's on by default, but when you're just starting with kanji and learning how readings work it's not very helpful.
Then go to the Experimental section of your user settings, and in the option for which kanji readings to test you on, select "No extra readings". This will make it so you will only be asked questions about readings you have seen in words before, so you will always have context for reinforcing the connection between the kanji and the reading. (Also toggle the button to show readings that aren't currently being studied in the same section, or else all of the readings you don't know will be hidden and it will look like all kanji have 0 readings.)
Don't overwhelm yourself.. Learn kanji when you're ready!
Even if you do learn a single kanji and all it's meanings it's still impossible to read! I'd suggest you learn vocabularyonly! Don't waste your time memorizing.. I think you kinda learn it along the way. Justavoid it when possible if it's too hard- you can come back for it later. It's easier if you don't struggle.
The best way to learn kanji is by learning the words they're used in. The first time Renshuu introduces a kanji flashcard to me, I completely fail to retain the information. But then when I start seeing it in words, it clicks.
As other posters in this thread have not quite actually said, becoming familiar with a character in isolation and using it in words are two separate skill sets. You need to practice both to fully master a character, although it is not necessary to do both at the same time.
