workout, Help me?!

hello:)

so i'm not really fat but im kinda chubby (and its gonna get worse if i don't do anything rn)...

I wanna start to workout and get fit,

and i'm not doing this for anyone but myself. I just wanna be healthy and everything & feel good about myself/confident...

(i'm 14y/o btw) but first of all it seems like it’s hard for me to lose weight/get fitter.

I’ve tried some workout apps but it doesn’t help. and I changed school after summer 2k19 & in my new school we have P.E four times a week...so I’ve been in this school for over 6 months now & I haven’t seen any difference at all even tho I work veryyyyyy hard. Second of all I have no motivation cuz I have depression.....how do ya’ll get up and start working out? any tips?

and why is it so hard for me to get fit/lose weight?