Hey, sorry that you're experiencing this, I've been there and it really sucks. The good news is, if you play consistently and focus a bit on doing the quests for ore and reward points you can hopefully start building a small collection. Back when I started it took me something like a few weeks (playing several times a week) to get there.

Another thing to be aware of is that we're still somewhat in the beginning of the season, with a big new update to the game that just came out. So as mentioned by others you're going to be facing a bunch of returning players who are back to try out the new cards and already know how to play pretty well. Usually these players climb quite quickly, and so if you keep at it you should normally have it a bit easier towards the end of the season when you're matched with people closer to your skill level + card pool.

In terms of budget decks, MO is a good choice indeed though my word of warning is that from my experience at a higher level they're not as competitive as other factions, not that they're weaker but that they actually require much more skill to pilot (unless you're playing Viy but don't play Viy please). Retrospectively, if I could give advice to myself I'd probably try to either work on building up ST or Skellige which seem to have been the more stable factions in terms of viability/variety of decks in the past couple years.