Do you have recommendations for beginner level resources?
Study Spanish is always my go-to recommendation for people who are just beginning
It goes from the basics of the basic to some fairly advanced concepts regarding the subjunctive and future/conditional, and mentions large portions of the overall grammar concepts
Secondly, my next suggestion is Conjuguemos
If you're a beginner my recommendation is to check out their section on the Tenses and Moods before anything
This is a good resource to have when you're going through any online activities or any homework you might have if you're taking classes since it has conjugation rules
And you can keep that tab open while you do their section on verbs which can help you practice conjugation skills, or you can head over to their grammar section
And right in that whole section you can see they have a vocabulary section which I have personally been using to help organize my thoughts for vocab lists
Another favorite resource for me is WordReference which is my favorite dictionary. I use it A LOT. Practically any time someone asks me a question I find myself checking the WordReference forums because in addition to helping you with words and looking things up, they have a forum where if you have grammar questions you can ask them - in my case, I find myself looking here first when I come across a phrase I don't understand or a word I'm not sure is regional
Additionally WordReference has a conjugation generator which is really helpful for looking at the complete chart of conjugations for verbs, especially the irregular verbs. And what I love about it is that I can also include the reflexive -se endings which helps more than you know especially later on
My other favorites are Linguee which helps me see translations and context for certain words or phrases, Spanishdict which does the same thing just more informal than Linguee (and also includes sections on grammar and vocabulary)
And a newer favorite is Forvo which lets you hear people say and pronounce words/phrases and names. This is really helpful for practicing your pronunciation and speaking, especially if you're not doing in-person learning and it helps get you used to hearing different accents in Spanish and also includes basic phrases that might be useful for you right on the main page
Past that, I really enjoy youtube channels that teach or talk about Spanish like Butterfly Spanish or Practiquemos and it's great for learning and listening practice, almost like you're in a Spanish class listening to the teacher. It's been very helpful to listen to Spanish-speakers, teachers, gamers etc since I graduated when I wasn't always hearing Spanish every day in my daily life
And as far as free apps, Duolingo is certainly the standard; it's especially been more useful since they added a forum feature and you can see native speakers and people talking about or reacting to specific prompts or questions, giving you context that you might not always know and sometimes people give you other options or mention other phrases or ways to say something
...I should also mention that these sources I mentioned are predominately what some might call castellano which is "Spanish", but it's official Spanish with the rules and standardized everything. There are many cases where native speakers will use other phrases or use language "incorrectly" in common everyday Spanish and that's much harder to learn because it's not standard and regularly seen and a lot of it is regional. I wouldn't worry TOO much about it if you're a beginner - all of the conjugation rules are pretty much universal, it's just vocabulary and the way some people phrase things that tends to be regional. Your more standardized and sometimes a little formal castellano will get you very far, and learning slang and regional Spanish is something that comes over time especially if you're planning on studying/working abroad or you're in regular contact with native speakers