I would recommend getting a job as an Jr. estimator.
Doing takeoff is only a fraction of what you need to know.
Closing an estimate (evaluating risk, labor factoring, O.T., man loading, cash flow, job expenses, etc) is something that takes a lot of experience to master.
Our evaluation process prior to bidding (is the GC our good customer, does he have the job, how many EC's are bidding, knowing how much the job is worth based on experience, man loading, etc) is almost as detailed as closing an estimate.
Most jobs I bid take me days or weeks to prepare. That's a big investment of time and money, so your odds had better be good.