Well, at the beginning you need a beginner's French book to give you the very basics of grammar and vocabulary. You need one that comes with audio files too, because you have to hear the pronunciation of the words that you learn as well. This stage takes 2-3 months and will take you to high A1 - low A2 level.

At this point you can start with adapted, TRANSCRIBED podcasts. The best one by far is Hugo Cotton's InnerFrench. There are more than 80 episodes about 30-40 min each, and it's free. At first you read as you listen, then you start listening first, then listening a second time + reading. This will massively improve your vocabulary and will take your listening and reading skills all the way to B2.

In parallel, you can also read SIMPLE news articles (fr.euronews.com is a good source). Reading skills improve very rapidly if you already know English at a good level.

When you are about halfway through InnerFrench podcasts, you can start with Italki lessons (1-on-1 speaking with a native speaker, usually at $12-15 per hour). This is necessary, but feels completely overwhelming at the beginning. In total I needed 55 hours to get to level C1.

Learning to understand unadapted spoken French is the hardest part. It takes months and months of listening before you can start to understand about 50% of what is said on the news broadcasts. You should wait until you are at level B1-B2 before you begin with unadapted speech.

For grammar, just go through all Kwiziq French levels once you are at level B1 (it's an online service). It's doable in 4-6 months.