I've played the game for like 10-15h around half a year ago and stopped. Picked the game up again after the new update and am struggling with re-acquainting myself with the controls, but I'll get back there I think. More importantly, I don't know when to take opportunities to come out and make plays.
For context, I played a round yesterday where I found the boss lair after a single clue which was in the neighbouring compound. I went there by accident and started the fight. Looking for a boss weapon, which I didn't know didn't spawn next to the boss lair anymore, I attempted the Assassin without a weapon and almost got killed. After wasting a sticky, I ran in the attic and hid there for like 35 minutes, listening to my surroundings in the hopes of finding a hunter. Fast forward a little, I managed to find a hunter that's been trying to kill the Assassin themselves for like 15 minutes straight and killed them, then I had like 5 minutes left to kill the boss and extract but didn't get it, so I just extracted.
Ultimately, I just spent 35 minutes in an attic doing nothing which wasn't as engaging. Any tips on how to make myself go out of my way to make proactive plays?
I would encourage you to get comfortable with a tool and consumable loadout somewhat, at least to try to keep them in the same slots and change your keybinds so you can quickly switch to a vitality shot or a melee weapon without having to scroll.
You can make loadouts just for those, but this game's UI is a buggy mess and the UX is guantanamo bay tier so I would wait with that until you feel 'rich' and always able to buy everything you like, so you don't get gear fear and frustrated with the fact that the game doesn't automatically use your contraband items.
For weapons, it's up to you. The Martini Henry is a decent gun, though I would say it's outclassed by the Sparks in terms of damage and by the Springfield in terms of special ammo. There are challenges in the game for making hunters bleed, or using specific weapons, etc. so being able to make use of multiple guns is useful. Challenges give bloodbonds and battlepass points.
If you feel like you want to play something varied one day, you can try out different loadouts, and if you feel like you want to get good with one gun another day, you can do that too. In the end, it's about your enjoyment.