I think SBMM isn't that tragic in ranked. I encountered predators in pubs, but rarely in ranked.Or maybe i simply cannot identify them(i'm platinum rank, hit diamond last season).
Even for beginner, i would recommend to play ranked as soon as possible. I consider it better than pubs. In pubs people often quit and leave you alone. In ranked at least they get a penalty for their behavior. The higher the rank, the more people care about game outcome and it is a bit easier to cooperate.
Try to stick to some forgiving weapons, before you know better the rest. For close range it would be EVA-8, it deals a lot of damage and its hard to miss with it. For medium/long range take G7 scout. It hits for 30 points in the body, fires fast, and has a lot of ammunition in clip. These two i consider as perfect for someone, who begins to play. You can also change it later for a Sniper rifle(which drain player's shield - and his confidence🙌).
It is actually a good idea to spent some time in the Firing range, shoot from some weapons, learn recoil patterns, legend's abilities and how they affect eachother. You should obviously stick to legend you like, but if i would have to recommend a legend for a beginner, it would be bangalore. Sprints faster when under fire and has smoke cover as tactical. I think its quite forgiving to play.
If its going about tactics, try to play safely. You may try to wait at the rings border for its closing, just to make an ambush. You will know, that at least from one direction enemy won't come, and it helps to prevent 3rd partying(shootout with multiple squads, in which its easy to die). Some legends(crypto, valkyrie to some degree) can detect how many squads are nearby and evaluate the risk.
I think its better to play with microphone, as without it - although the ping system is great - people may not be able to understand you. I played a lot with it, rarely met with toxicity, although you never know what MM throws at you. It also requires(a lot) of composure.
Other tips, which you may already know: don't stay still while looting deadbox, slide and jump often to avoid fire. And most important - add to friends people, with which you had good games or join a club.
