The workouts soon let you know if things are wrong. 
The plans are designed to go: Base → Build → Speciality so jumping in at Build tends not to be ideal. Base gets you ready for the much harder efforts in Build so shouldn’t be missed. Spanish Needle is one of the tougher workouts BTW.
Depending on your level of effective training before starting TR I’d look at either Sweet Spot Base Low Volume 1 or 2. Low Volume doesn’t necessarily mean “easy”, the workouts still make you work. Do another Ramp Test, be careful just which option you press at the end, the text isn’t particularly large and it’s easy to get things wrong and discard the result. Don’t worry about the actual number produced, it’s just a guide so that the workouts match your ability.
Have a look at the TR YouTube channel https://www.youtube.com/trainerroad there’s a playlist about testing plus there’s all the podcasts some of which cover testing and which training plans to choose. There’s also “Plan Builder” which is there to help you with all of this.