Tools must have

I am a new member to this amazing community and enjoying learning. I
realized Straddles and Calendar Strategies are the bread and butter for
SteadyOptions trades. I am overwhelmed with all the information and
learning on this and have decided to narrow down my focus and have
decided just to master these 2 strategies and spend time as much as I
can.

That said what are the must have tools to understand why certain trades
are taken? I would like to understand how we look for a potential trade
and how we decide to go for a specific trade? Do I need to buy any paid
subscription or do I need to install any software free or paid to be
able to achieve my goal?

Basically what are the must have tools to master the in and outs of the 2 Strategies?