Question about leveling past 70-ish.

Hello all,

First time that I'm leveling a char above like 40-50lvl and I'm kinda lost. I have a barrage rogue 74lvl and I have no idea what to do to level up. I get obliterated in nightmare dungeon and I cannot unlock The Pit. Other summoned dungeons I get destroyed and one shot too.

I had some infernal compass T1 and I did them. Do I continue helltides or?

I tried looking at youtube and websites but to be honest I got even more confused. I feel like because I cannot enter more high end dungeons I cannot get better equipment and I struggle.

Any pointers into some youtubers/websites that is explained for newbies will be much appreciated too.