Which is the best Twitter growth course you would suggest?

My situation:

• I have a Twitter account for 14 years now
• Never actively tweeted
• I follow around 100 accounts
• I have 30 followers, I assume most of them are bots / non relevant followers
• I want to start being active on Twitter and grow my account.

Which is a good course you would suggest to me? Could be either paid or free.

Thanks in advance!