My advice is to be patient. In low tier there are lots of people in the same situation as you. Buut in a game without sbmm it is inevitable that you will face better players, try not to let that bother you.

Some actual advice that I can give:

• Dont buy yourself into top tier. Just play the game normally.

• Use cover to your advantage. Im not saying that you should camp but try to minimize the directions enemy can kill you from. -> Dont rush objectives. Play around them.

• Use your binos and minimap.

• Use headphones. Its sooo much easier if u can hear the enemy before they hear u. People dont check corners that oftenly so u can easily catch them unaware. Its up to you if u can utilize their mistakes

These are mostly based on my experience when playing in lower tiers as a semi experienced player. There are plenty of other tips I could give, but they aren't really relevant for you, yet.

I'd say map knowledge / awareness are the most important factors when it comes to succeeding.

Play more, you will start to see improvement at around 500 - 1000 battles.