Hmmmm, I guess since you're very familiar to BASIC, I'll write a similar routine in both, this takes the value 16, stores it in a variable and keeps adding 10 to it until it's greater than or equal to 100:
BASIC10 DIM MYVARIABLE
20 MYVARIABLE = 16
30 MYVARIABLE = MYVARIABLE + 10
40 IF MYVARIABLE < 100 THEN GOTO 30
ASMMYVARIABLE: .DS 1
LDA #$10 ; which is 16 in hexadecimal
STA MYVARIABLE
loop:
CLC
ADC #$0A ; which is 10 in hexadecimal
CMP #$64 ; which is 100 in hecadecimal
BCC loop
STA MYVARIABLE
There's some subtleties to do with exactly where in the NES memory you can declare that variable, but essentially those two routines do the same thing.
Sorry, I'm not sure where else to point you, but asking questions here, on the nesdev forums, or in the chats should get you started