There isn't much way of knowing - everyone advances at different paces and there are a ton more variables such as what time control you will be using (you can play more games of a shorter time control, but it will also have more variance).
I think the best way is to probably set a reasonable goal like 1000 chess.com rating (preferably rapid; bullet and blitz are not best for learning) and work towards that. Based on your progress speed, you may decide on choosing a higher rating like 1100 or 1200. How long will this take? Who knows? The average chess.com rating is about 1200 (I'm leaving out a bunch of details like rating pool, time control and accuracy of rating being representative or not), so this means that half of the players on here NEVER reach this rating.
The good news is that 1000 and even up to 1200 is VERY reachable if you are willing to put in the work and time (which you are on the right step for already it seems).
Maybe set a goal of 1000 for the year and if you reach 1000 quickly, then change it to 1100 or 1200 by the end of the year 2021. Good luck and have fun with the chess learning
I just started playing chess toward the end of November and earlier this month I decided I would commit 2021, to the maximum extent practical (being a father of 3 and a full time teacher), to becoming the best possible chess player I can be.
That being said, what's a reasonable rating to aim for within a year's time? 1200? 1500? I paid for a platinum membership here and I've mentally committed to about 2 hours a day to studying, practicing, and (naturally) playing chess. So far it hasn't been difficult because it's so enjoyable. But I want to write down some measurable goals and wanted to make sure I'm on the right track.
I'll provide more details of my gameplan if anyone is interested.
Thanks in advance!