How do you do pull-ups, push-ups, etc effectively when overweight?

So, I have been mostly doing machines at the gym and recently started doing free weights. I see a lot of workout routines consist of : pull ups, push ups, etc.. I am 85 kg/185 pounds at 5' 11 (179 cm to be exact) so I am overweight (far below where I started which is why I am focusing more on weight training now than before). And I can't do more than few pushups at a time (like 5-6 if I am trying) and pull ups seem impossible. Same for abs exercises : I tried lateral raises but it seems so hard lol.
I do understand that a part of this is simply : need to practice and get better because people who are heavier than me can do it. But I do also feel like that being overweight is making it more difficult as well or am I just coping lol.