Help me do this.
Help me to do this.
These two sentences are both correct. It all depends on the verb and how frequently it is being used. For the verb “learn” the most common way to say is “help to learn” and also for the verb “do” the most widely spoken form is “ help do something”. Anyway, you could check out this site https://bigben.academy/help-learn-or-help-to-learn-english/ to have a better understanding.