There is not a future verb tense, you do not have to change the verb. In the sentence, express when you are going to do the action in present tense. Future tense: 来週、友達の家に行きます。 I'm going to my friend's house next week. Present: 友達の家に行きます。I'm going to my friend's house. The に particle can be used instead of nothing, it emphasizes the date the action is going to take place. 来年にアメリカに行きます。

「つもりです」 and 「でしょう」 express the future tense without a future time word. e.g. "I will go to my friend's house." 「私は私の友達の家に行く　つもりです。」. "He will go to my friend's house." 「彼は私の友達の家に行く　でしょう。」.

I think this is a basic but a tricky question. I'm not a teacher, but please let me try to explain this to you. As for conjugations of verbs in Japanese, we have only two forms, a dictionary form and ta-form. (Sometimes a dictionary form is called non-past form (非過去形（ひかこけい））, whereas ta-form is called past form(過去形）. You will be able to understand if you read further.) Ta-form means for past tense. A dictionary form of action verbs such as よむ, たべる, いく, のむ, means future tense, whereas a dictionary form of static verbs such as いる, ある, means present tense. 　 ◎an action verb ending sentence ・future tense: use dictionary form #1（わたしは）ほんを　よむ／よみます (I will read books.) #2　カフェで　コーヒーを　のむ／のみます (I will drink a coffee at a cafe.) ・present tense: use て-form of an action verb + いる／います （わたしは）ほんを　よんでいる／よんでいます (I read books.) カフェで　コーヒーを　のんでいる／のんでいます There is an exception. When a dictionary form goes with a phrase expressing something habitual, the sentence becomes present tense. #1' （わたしは）『まいにち』ほんを　よむ／よみます (I read books every day.) #2'　カフェで　『まいあさ』　コーヒーを　のむ／のみます (I drink coffee at a cafe every morning.) ◎As for a static verb ending sentence (including an adjective ending sentence), a dictionary form means present. If it's necessary to make it future, just add a phrase expressing future. (I feel somehow that we rarely use future tense for these sentences though.) ・present:がっこうに　せんせいが　います ( Teachers are at school.) ・future:らいげつには　ここに　あたらしい　せんせいが　います ( A new teacher will be here next month.) I hope I won't make you confused.

It kinda depends on what you want to say. But I believe -masu can generally be used in combination with a future time word to suggest future tense. For example: Ashita ha ramen wo tabemasu I'm gonna eat ramen tomorrow.