There's a good selection of ways of referring to future events in these extracts. The form "will be (+ing)" always refers objectively to future events arranged for a
specific time, such as in the extracts about the occupational safety meeting next week and the "Stop Smoking" sessions next month. The other "will" form, such as "will give up" and "will attend" in
the "Stop Smoking" extract, usually refers to the future too, but in a subjective way, expressing expectations or assumptions (the organizers guarantee...), or a polite form of command/instruction
(participants will attend...).
Events which are happening as part of a fixed schedule are referred to with the present tense: "first course session takes place on May 3rd" or "each one lasts...".
The present tense also refers to the future after "If...", because it represents a condition which starts in the present (in the English way of thinking) and continues into the future: "If anyone
needs further assistance...". The main part of the sentence contains "will", referring to the result of the condition being fulfilled (probably).