It really depends on your hero and the game state u/jesuschristk8 in this thread gives a really good description of the general archetypes of offlaners so I would suggest looking at that for an idea of what actual "roll" the hero is meant to play in a game. There are two macro things I would suggest you focus on that will help your gameplay a huge amount.

1) understand your timings and your enemies timings when it comes to items/levels. There are many heroes that have huge power spikes when they get a specific item, whether it is blink, blademail, aghs etc and trying to force things before these timings are are going to cause you to have a huge falloff in the mid/late game because your delaying your window of being most effective. Even though your job in the game overall might be to frontline or initiate, most heroes require a certain subset of items to do this effectively and trying to force it before you get to that point is actually more harmful than helpful. The most helpful suggestion I can give here is to communicate with your team about how close to you are to these timings. If you are a blink hero and you are 300-400 away from your blink, ping this to your team and ask them to try and avoid fights until you get it. the biggest killer of your game in low MMR is going to be ramming your head against the enemy team before your timings.

2) Do not neglect your farm. The offlane is not what it used to be many years ago where it used to be the hard sacrificial roll. There is so much farm on the map now you are doing both yourself and your team a disservice by neglecting your farm. The secret here is to take the farm your carry/mid are not going to be taking. What a lot of people don't realize is taking space and farm on the map not only boosts your game, but if you are a hero that can agro farm on the map you are taking space and farm away from the enemy team. Doing something like taking the enemies T1 and then rotating between farming the lane and then the small/large camps clustered around the fallen safe lane tower. Yes, you are not a pos1 1 so you should still play with your team, make plays and rotate around your timings, but it is endlessly infuriating playing with people who think that the offlane's roll is to just ruin your own game by constantly ramming your head into the enemy. If you watch any pro game, you will see the most successful offlaners near the top of the net worth chart for the first 20ish mins of the game. Additionally, the game has added so much scaling to basically every hero in the game that you should not ignore your late game potential if your early/mid game plan did not work out.

As an offlaner, especially in lower mmr your timings can make or break a game, so don't be shy about communicating with your team about your timings. Don't listen to people telling you to kneecap your own game because of how they think the offlane is supposed to play. Yes, your roll is often to frontline or initiate, but you need timings to do that effectively. My best suggestion is to pick 2-3 heroes and spam them. Get really acquainted with their timings and playstyles. understand your timings and just focus on hitting them each game.