Be prepared to spend a LOT of time putting your proposal together. They tend to be vague and unsure of what exactly it is that they want. You can be their consultant at no cost basically and help them spec everything but it is time consuming and then you still might not get the job. Also depending on the size of the job you almost might need to get setup in a bunch of systems like SAM, DFAS, WAWF, all of which have their own requirements. You will need a DNB number as well and figure out what your cage code is. Its a lot and it can be very complex. Enough so that it discourages many from trying. I've put 40 hours in a proposal before that was close to 30 pages long....
The forms are a lot of fun too. You need to certify that you are not transferring technology to North Korea, not using child labor, no collusion, etc, etc, etc. You basically have to attest to a hundred different things. lol
All that being said, because they are sometimes so complicated, there sometimes will not be another bidder or only one or two others. When you are small and just getting your feet wet with federal work, it can be very intimidating. They can also be very profitable. Getting paid can be a slow process too as it has to go through the contracting officer and multiple approvals that the jobs is completed to the requirements outlined in the scope of work.
Also once you get setup in SAM. You will start getting spam and calls from hundreds of companies who will offer to get you setup in all the systems for you, for a price of course. They really want to push to get you on schedules. Those are set pricing contracts.....