I'm fairly new to camping, and completely new to backpacking. I've bought some gear and I'm having a hard time getting it all packed. I bought a 30L pack which from what I understand is good enough for day hikes and overnight camping. Now day hikes seem totally possible with my pack, but my tent, rainfly, sleeping bag and pad take up like 80% of the space. I have the sleeping bag compressed as tight as the bag will allow and tried to back everything else as tightly as possible making sure there's no air pockets. I could fit my other gear in pretty tight but things like food and clothing would have no room.

What am I doing wrong? I've been contemplating returning the bag and getting a larger one since I would like to work upto multi day hikes.