Back in the days of the Veteran system it would be a bit of a issue... but! Now days no worries! Do not worry about it, you earn Champion levels/points(CP) for just playing how you have been. If you like the story and you are enjoying the quest, just keep playing. I recommend everyone plays the story/quest all the way until they at least finish Cold Harbour and their starting alliances story.

Keep up what your doing and stick to your natural progression path and youll earn yourself a decent start towards CP160 which is your next goal after finishing the main story quest.

Honestly after you finish the main quest or even before it, its up to you. Do you want to go start and do the AD or DC main story? Do you just want to start knocking off accomplishments and goals from your achievements section? Maybe take some time and dabble into PvP and explore Cyrodiil for a while(lots of dungeons/delves and content in Cyrodiil).

Bottom line is dont stress about it... CP are easy and come fast, especially if you use Enlightenment(youll need to learn about this as well) to your advantage. This is also a great time to try out and start and alternative toons you have been wanting to try. This gives your main time to build up some enlightenment when you use it all up.

Just dont worry about the CP Grind from 1-160, its not too bad and you only have to do it once. What many new players often forget or do not realize is you wont have to do that part again. So say you hit level CP100, when your next character hits level 50 they automatically go from lvl50 to CP100, as CP levels are account wide so every character you have at level50 will always be the same CP as your other level 50s.