I’m a native English speaker, so can’t really help with that part of it. But I have my own fledgling channel *coughplugcough* and here’s what I can tell you from a lot of research and a lot of YT watching.
1) Biggest thing you want to do is research copyright and fair use. YouTube does have a copyright “class” video. Watching a few minutes of one of your videos, without being fluent in Spanish, looks like you might be on top of that already.
2) If you’re looking to get serious with your channel, def invest in better equipment, if you can afford it. I was fortunate enough to where I could actually invest a bit of money into my channel at this time, once I decided to get serious with it. A quality mic will make a big difference. I’m using the Yeti Blue mic. It’s a great mic at a mid-range price. There are other mics out there. This one seems pretty popular though, unless/until you’re willing/able to go high end ($400 or so).
3) While I can only understand bits and pieces of Spanish, your editing seems solid. I’m fairly confident that I can get the gist of what you’re saying just from the way it’s spliced together, lol. Haven’t used iMovie, so no idea how complex you can get with it. I’m actually using an editing program called Filmora9. You can use it free, but it’ll add a glaring watermark on the video. If you’re willing to invest in your channel, you can get a license to use it without the watermark for a not terribly huge investment. Beyond that, I’m really not sure. Feel free to check out some of my videos if you’re curious about Filmora9 and what you can do with it. There are a lot of tutorial videos on the program as well. I’ve learned some fun tricks with the program. You do have to pay a bit extra for a lot of the useful special effects though (martial arts pack is free and I use it a lot). Once again, that depends on how much you’re looking (and able) to invest in your channel from the start. I’ve been very fortunate and blessed in that regard, considering how crazy things have been.
4) It also depends on what exactly you want to do with your channel. If you want to keep it simple in design or do something more complex. I have a pretty creative spirit, so I’ve been going all out on the video editing and whatnot. It’s not necessary though in order to build a successful channel. All depends on what you want to do with it and what you want to focus on.
5) Don’t try to do too much. ie: I’m starting off with SWGOH, while looking to expand a bit within the gaming/pop culture genre. Don’t try to do travel videos, food videos, 18th century life videos, eating mre videos, gaming videos, garage engineering videos, underwater basket-weaving videos, etc, all at the same time. If you get too diverse, you’ll lose your core audience.
6) Thumbnails! Get good at them! It’ll probably take some practice. They have to grab peoples’ attention, while giving them a good idea of what’s in the video. I’ve already gone through a few different formats within the short time I’ve been doing it. Definitely made improvements with each iteration. If you can grab their attention with the thumbnail, you’ll get the chance to hold their attention with your video.
There’s a lot of other tips people can give you. You can also search for tips on YouTube. I’ve seen several vids where people shared their biggest mistakes when starting off. Way too much to post here, but I highly suggest doing a bit of research that way. It will help immensely. Good luck to you!