Average queue time at Sagrada Familia, best time to visit and tickets?

Good day,

Spending 2-3 days in Barcelona next week. With that little time I prefer not to stand in line too long but I don't want to miss out on this experience either. Wondering if we should go ahead this time or wait as I'm hoping to visit the city again next spring.

In June/July, what are the average queue times at La Sagrada Familia to get inside? And is there a less trafficated time of day to visit? For example less people during morning time or evening?

Also, when looking up tickets to prebook I'm finding many options but very unclear if there is a "main" website. Any recommendations?

Thank you very much.