Congrats on your first boat. Lots of fun ahead!
If you are not used to backing up a trailer, I would suggest that you go to a school, church, etc parking lot during off hours and practice before heading to a boat ramp. Also, when at a lake, be sure to prep the boat by organizing all boat gear (docking lines, etc), fishing gear, coolers and putting in the plug (you will eventually forget to do this one day! Almost everyone does.) plus removing the tie down straps- all while away from the ramp and BEFORE you start backing to launch. This allows for an efficient flow of traffic and is the only way to be considerate of those launching and removing their boats from the water. Blocking the ramp is considered a rookie mistake and/or bad form at best and can lead to intense discussions with those who are being impeded by such unnecessary thoughtlessness. Same deal when putting your boat on the trailer at the end of the day- pull the boat out and, only after vacating the launch area, clean, drain and dry and put everything away. Had a clown block a ramp at Chatty yesterday but didn't care to engage so he got away with it. No sense in starting off your boating career in a way that will leave a bad taste.
Be safe and enjoy.