Unfortunately, if you don’t have an opportunity to seriously practice regular conversation with people, length of studying won’t do much. You should develop some literacy over time but getting the hang of tones and the language structure, in my opinion, is something you have to do in practice along with study. I have met very few people who only studied Chinese in the US who could actually speak with any fluency. In China, lots of foreigners don’t try to learn it, but those that do make the effort learn fairly quickly. I studied formally in China for a 10-week program, then spent about a year there in total, often in small towns with few English speakers. Getting up to a level where I could get by for the most part and have decent conversations was not hard at all.
If you have people who you can reliably practice with, go for it. If not, you might be better off studying something else, or contenting yourself with getting ok at Chinese writing and waiting for an opportunity to get your speaking in order in the future.
Standard Mandarin is originally a constructed official language based on the Han Chinese dialect spoken near Beijing. Many Han Chinese areas have dialects that are never called languages because the Chinese government already has enough problems with nationalisms. Many of these dialects, however, are mutually unintelligible with Mandarin, even if grammatically they can be similar.
Randomly Chosen Example:
English: He said, “I am an American.”
Mandarin: Ta shuo le, “wo shi mei guo ren.”
Zhuji Dialect: Si gong ge, “nyo ze mei go ning.”
The most diverse dialects are in the South, and Zhejiang and Jiangsu have many distinct dialects. Recognized ethnic minorities in China are usually recognized as having their own languages, separate from Chinese. These include Mongolian, Uighur, and Tibetan.
After the Communist takeover, there was a movement to consider language reform. Some wanted to abandon the Chinese writing system entirely in favor of an alphabet. What they eventually did was “simplify” a bunch of common characters by reducing the complexity of their strokes. Areas of China that they did not control did not adopt these reforms, and they use “traditional” Chinese. Most characters remain the same and it is usually not a big effort for Chinese to read the one they are not used to using. That said, Chinese who grow up using Simplified often have a harder time dealing with classical Chinese, because some of the relationships between characters were obscured by the simplification.
I think a classic way to go about it is to treat reading, writing, speaking, and listening as fairly discrete subjects in studying, and then bringing them together in practice. You will have to write the characters a lot to remember them. I just have my own experience on this. I think there is a split on how much pinyin should be emphasized, but it will come in very handy for typing. Most Chinese learn at least basic pinyin too, for this reason.
The most annoying thing for me in China learning Chinese was that if I saw a character or a sign or something that I didn’t know, I couldn’t ask a friend about it later unless I took a picture or wrote it down. It made it hard to absorb words from the environment. I think, though, that there are phone apps that can help with this a lot.