So the thing is that Chinese is an uninflected language. This means that words such as nouns, adjectives and verbs don't change their forms to reflect grammar. If you think of past tense, present tense and future tense, you're on the wrong track. Chinese doesn't have tenses. So, the verb is not conjugated to reflect the time of the action. You communicate the time of the action by saying when the action happened or will happen (e.g. today,tomorrow, yesterday, this week, last week, next week, etc.) In Chinese, you say "today I go to school", "yesterday I go to school", "tomorrow I go to school". The verb "go" doesn't change. Any other words that you add to the verb reflect some idea other than just time. 要 means "want" but I could say "今天，我要上学" "明天我要上学" "昨天，我要上学", The same is true for 将 and 会. Well, 会 may be a little different because it means "can, am able to" and so if you say "昨天，我会上学", it kinda means "I could have" or "I was able to".

要，将要，会 all of them can means future tense,but normally we would add time key word,like 过会儿in a minute 明天tomorrow 下个月next month eg.我过会儿就会到。I will be there in a munite. 我下个月要去德国。I will go to Germany next month.