Steamworks sdk should allow for easy integration of achievements and login etc but I would not recommend spending development time on achievements from the start. They are unlikely to get you any significant engagement unless your game is are already eligible for trading cards and has a substantial userbase.
Controller support with the ability to remap controls will be very helpful as well as language localisations. You can release your game to early access ot grant beta access to limited users to gauge interest. Once you have a thousand or so users, it should be easier to see which regions the bulk of them are from and can guide your decision making with regards localisation and other features
Connecting with some users on steam who have played and enjoyed your beta builds can prove helpful whether it’s for translations or just requesting them to spread the word, post in their groups and so on. Steam has powerful community features and my opinion is this is the best starting point to promote your game pre-release
Twitter is great for identifying streamers who might be up for featuring your work and joining in the twitch streams and participating there is a good strategy towards expanding your network. Without a massive marketing budget, the best thing you can do is to make a killer game and then engage extensively with the gaming community.
All the best!
Edit: once you are able to get an early access build and store listing approved, consider signing up for woovit to allow content creators to discover your game a d request keys for reviewing it. There are other similar platforms like catapult.gg and keymailer which you can also consider
