F.F. Bruce, one of the outstanding evangelical scholars of the 20th century said that verse 16 is awkward Greek. If you find it difficult to translate, just know that you are not alone. This is a difficult verse to translate.
Pass #1: Translate as many words as you can on your own. Here are worksheets you can use:
Pass #2: Use your reader's edition to fill in the words that are used 30 times, or less, in the NT.
At this point, see if you can manage any sort of translation of these verses, even if it is only fragmentary.
What If I Don't Have a Reader's Edition GNT?
Click to see purchase options...OR you can download a reader's-style list of rare NT words for each verse here:
Pass #3: Go to StepBible and fill in all the remaining words.
Please do not give up on listening to, and speaking, Greek. These activities engage regions of the brain that are very much involved with language acquisition. Listening/speaking will help you learn to read better.
First, read these verses on your own, out loud.
Second, listen to John Schwandt read the verses at full speed.
If you find this difficult, then listen to John 1/3 slower.
Acts 3
11 Κρατοῦντος δὲ αὐτοῦ τὸν Πέτρον καὶ τὸν Ἰωάννην συνέδραμεν πᾶς ὁ λαὸς πρὸς αὐτοὺς ἐπὶ τῇ στοᾷ τῇ καλουμένῃ Σολομῶντος ἔκθαμβοι.
12 ἰδὼν δὲ ὁ Πέτρος ἀπεκρίνατο πρὸς τὸν λαόν, Ἄνδρες Ἰσραηλῖται, τί θαυμάζετε ἐπὶ τούτῳ ἢ ἡμῖν τί ἀτενίζετε ὡς ἰδίᾳ δυνάμει ἢ εὐσεβείᾳ πεποιηκόσιν τοῦ περιπατεῖν αὐτόν;
13 ὁ θεὸς Ἀβραὰμ καὶ ὁ θεὸς Ἰσαὰκ καὶ ὁ θεὸς Ἰακώβ, ὁ θεὸς τῶν πατέρων ἡμῶν, ἐδόξασεν τὸν παῖδα αὐτοῦ Ἰησοῦν ὃν ὑμεῖς μὲν παρεδώκατε καὶ ἠρνήσασθε κατὰ πρόσωπον Πιλάτου, κρίναντος ἐκείνου ἀπολύειν
14 ὑμεῖς δὲ τὸν ἅγιον καὶ δίκαιον ἠρνήσασθε καὶ ᾐτήσασθε ἄνδρα φονέα χαρισθῆναι ὑμῖν,
15 τὸν δὲ ἀρχηγὸν τῆς ζωῆς ἀπεκτείνατε ὃν ὁ θεὸς ἤγειρεν ἐκ νεκρῶν, οὗ ἡμεῖς μάρτυρές ἐσμεν.
16 καὶ ἐπὶ τῇ πίστει τοῦ ὀνόματος αὐτοῦ τοῦτον ὃν θεωρεῖτε καὶ οἴδατε, ἐστερέωσεν τὸ ὄνομα αὐτοῦ, καὶ ἡ πίστις ἡ δι᾽ αὐτοῦ ἔδωκεν αὐτῷ τὴν ὁλοκληρίαν ταύτην ἀπέναντι πάντων ὑμῶν.Third, practice pronouncing these verses, phrase by phrase, with John.
...to learn whatever you can from them.