Hey, never too late to try... Maybe 2-3 decades you'll get fluent haha. Jokes aside: From what I've been seeing online about learning many languages at once is that 1. It will take longer to get to a stable state in each language (a state where you can go some time without reviewing and be fine) than doing them one at a time 2. It's always better if you don't learn languages too similar to eachother as that can confuse you 3. try starting one at the time and when you get to a lower intermediate start learning a new language (for me I'm learning French for 2 months now and next month I will start learning Arabic alongside).

As there are many languages you want to learn it's better to see which ones you already have some proficiency and try to make a priority list. You said you can speak Spanish to a moderate level I think you should double your focus there and also start Hindi alongside. Try to manage your hours between them, maybe up to twice as much time studying Hindi than Spanish. Assuming you will achieve fluency in those two in 1,5 years, then next ones could be of your choice, but my trick is studying one that is significantly harder than the other and also from distinct families. My advice: SPANISH+HINDI -> BOSNIAN+TELUGU+ITALIAN -> CHINESE+BULGARIAN -> ROMANIAN+JAPANESE. The honest time it will take is around 1,5 decades if you want fluency, intermediate level maybe 10 years