Yes, if something is destroyed you cannot use it again. This is an integral part of EVE and something you should consider when logging on. Eventually, after several losses you will start getting the hang of it and will begin destroying more than you lose (hopefully). Getting wet is part of swimming.
What most of us do is we will have several fitted ships ready depending on our skills, play-styles, and functions.
This way if (when) our ship is destroyed all we gotta do is fly back and get into the next one.
You will find it very useful to set up an F.O.B. with several ships you are well skilled in (both in-game skills and which you feel comfortable using) in a stable Low-Sec border system (either a High-Sec system bordering the Warzone , or a Low-Sec system in the Warzone with access to High-Sec nearby (1-2 jumps)) and install your “Medical Clone” (respawn) at the F.O.B. for the duration of your Enlistment.
If you are in a Corp you will likely be advised where to set up F.O.B. and it will usually be where the Corp also has assets, making the sharing and swapping of modules and ships between the Corp much easier.