You can go some different routes, there's a lot of options to use.
If you prefer rifle/mmr then you can just use the meta rifle build which is using bakers dozen/classic m1a rifle, which does the best damage right now but will be nerfed soon. They tried to nerf it last patch, but because it was left out of the notes they caught backlash for it and rolled it back, but they will nerf it. But you can build it for 60% crit chance(that's the cap) crit damage, head damage, fox'a prayer kneepads, contractor's gloves. providence pieces the rest.
MMR build can use 4 piece aces and eights gear set, pristine example airaldi holding chest for perfect focus. Or full set airaldi, 1 piece providence. For the mmr use the nemesis exotic, or white death for highest headshot damage(gets like 25% more than other mmr's. For skills on these builds typically something to heal and revive hive.
For a skill build running turret/seekers, can go different routes here, use the gold pieces to build for skill level, haste, power with technician. You can go bomber route with Demolitionist and use artillery turret in it with seekers. You can also go seekers with hardwire set which has the set bonus of resetting one skill when you use another every 20s, you can lower that to 10s with the hardwire backpiece talent, and basically you set out seekers, then drop either a hive or pop shield(these two you can quickly deploy and pack up) and reset the cooldown for seekers every 10s. You can also get skilled talent on chest piece and get the seekers to reset after every skill kill(this talent can go nuts in the art turret/seeker build).
As for progression... get shd levels, fill out the recal library, do the seasonal stuff, raid I guess, while constantly trying to upgrade gear.
New meta this week is going striker drone(it's survival got buffed last patch), with assault turret, build with tech, skill levels, power, haste.
A lot of other builds out there, this thread probably outdated now but has a lot of build examples in it
And the gear sheet is around if you want to put something together on your own.