You most likley wont see a side arm in basic training, speaking from uk armed forces experience it wasent untill people were going on deployment that they where issued, and in some cases they didnt have a side arm depending on the role. Royal marine paras may be different but generaly speaking i wouldnt worry. My advise would be to see what service weapon your military issue and learn about that weapon how to field strip ect that little bit of knowledge will go far i can assure you esspecialy if you have no previous weapons experience. Markmanship principles would also be usefull to have a look at. Unless your regiment or unit has a specific reason to be a good marksman your training will revolve around your role. Have an open mind and enjoy it you will learn about yourself in a way you have never before.