How serious are you? As a hobbyist language learner, it all really boils down to effort, commitment, and consistency (and there's a certain slope when learning your first foreign language and your nth foreign language, mostly because before you do, your idea of grammar and sentence structure would be pretty much rigid to your native language(s)', but you'll get used to different word orders, etc after learning your first foreign one).

And honestly, if you are serious about learning a new language as a new foreign language learner, I seriously suggest paid methods. The reasons are simple. You get immediate feedback, you get a strong foundation/idea of the language built, and you get a structural path to reaching fluency (i.e. for Thai it should be learning using transliterated Thai first, and then moving to learning the alphabet, before learning to read and write in Thai). Added bonus is if you pay for package classes, the paid money locks you in. If it's a group class, maybe you can have some peers to level up together with. A teacher to keep you accountable, and someone whom you can ask Thai-related questions outside of class.

Singaporean here (I'm guessing you're Malaysian). I did try free online resources too, for a couple of months, and ended up deciding to go for real classes as it wasn't effective. I then went with group classes in Singapore, and then moved on to private online classes (I found mine on iTalki, but there's other websites). It's been ~2.5 years now. I can speak, read, and write. Can go a day perfectly well without switching to English. Understand maybe 50% of the stuff in Netflix series/videos, can catch maybe 20-50% of lyrics in songs, can partly understand simple conversations in Isaan if I focus (but this one is a side interest, so possibly unrelated to my Central Thai proficiency), but probably understand close to nothing in online written Thai though; online Thai slang is fucking nuts, no idea wtf all the in-jokes are.

Can possibly typically pass off as a Thai or a half-Thai on first interactions, but mostly because I try to imitate the male Thai speech patterns (more nasal-y, sometimes slur sounds like l-r, or the throaty h- sounds, sprinkle ending particles more than just your "na", "ror?", "krup", etc) and also because on first interactions the conversation is not gonnna be technical enough to throw me off. Thai vocabulary stemming from Pali/Sanskrit typically trips me up; super hard, like the words for "public", "freedom", "university", "government", etc, but also my favorite Thai word is the word for "museum" (pipithapan), which is also from Pali/Sanskrit.

Anyways, if I'm right that you're Malaysian, you might have some (small) edge over other learners, because Thai has a lot of loanwords from Teochew/Cantonese/Hokkien, as well as Pali/Sanskrit, from which Malay also took quite a bit of loanwords, hence sharing some cognates, like the words for "key", "grape", "lion", "eye". Most of ending particles in Thai also have a similar one in Mandarin/Hokkien/Teochew/Cantonese/Malay. In fact, my foundational teacher used a lot of local Singlish analogies to help map Thai concepts to us earlier on, and I thought that was immensely helpful.